Glossary of botanical terms

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Many of the terms used in Wikipedia glossaries (often most) are already defined and explained within Wikipedia itself. However, lists like the following indicate where new articles need to be written and are also useful for looking up and comparing large numbers of terms together. Terms relating to Plant morphology are included here as well as at Glossary of plant morphology.

This glossary is incomplete; you can help by expanding it: you can also help by adding illustrations that assist an understanding of the terms.

A[edit]

abaxial
The side away from the axis, for instance the lower surface of a flowering plant leaf.
abort
To abandon development of a structure of organ.
abscission
(adjective abscissile): A plant's normal shedding of an organ that is mature or aged, e.g. a ripe fruit or an old leaf.
Acaulescent Welwitschia
acaulescent
An adjective descriptive of a plant that has no apparent stem, or at least none visible above ground. Examples include some species of Agave, Oxalis and Attalea.[1]
accrescent
Increasing in size with age, such as a calyx that continues to grow after the corolla has fallen, for example in Physalis peruviana.
-aceae
The suffix added to the stem of a generic name to form the name of a family.
achene
A dry 1-seeded indehiscent fruit; e.g. members of the Ranunculaceae.
acicular
Slender or needle-shaped. See Leaf shape.
acropetal
Moving from roots to leaves, e.g. of molecular signals in plants.
acrophyll
The regular leaves of a mature plant, produced above the base; usually in contrast to bathyphyll.
acrostichoid
(describing a type of sorus) covering the entire abaxial surface of the frond, usually densely so, as in Elaphoglossum and Acrostichum.
actinomorphic
regular; radially symmetrical; may be bisected into similar halves in at least two planes. Generally applies to flowers in which the perianth segments within each whorl are alike in size and shape; compare irregular, regular, zygomorphic.
aculeate
Armed with prickles; e.g. the stem of a rose.
acuminate
Tapering gradually to a point.
acute
Sharply pointed; converging edges making an angle of less than 90°; compare obtuse.
adaxial
The side next to the axis; e.g. the upper surface of a flowering plant leaf.
adnate
Fused to an organ of a different kind; e.g. a stamen fused to a petal; cf. connate.
adventitious
A structure produced in an abnormal position; e.g. an adventitious bud produced from a stem rather than from the axil of a leaf.
adventive
Introduced accidentally (usually referring to weeds).
aerial
Of the air; growing or borne above the surface of the ground.
aestivation
The arrangement of sepals and petals or their lobes in an unexpanded flower bud; cf. vernation arrangement of leaves in a bud.
affinis
With affinity to others, akin to; often used for a provisionally recognized but unnamed taxon considered close to that name, perhaps a hybrid or extreme variant.
aggregate fruit
A cluster of fruits formed from the free carpels of one flower, e.g. blackberry; cf. multiple fruit.
agricultural weed
see weed.
alate
having a wing or wings.
-ales
Suffix to the stem of a generic name or descriptive name to indicate that it applies to a taxon of the rank of order.
alien
Differing in nature, foreign; a plant introduced from elsewhere (exotic, introduced, non-native, non-indigenous).
alkaloid
Molecule with a nitrogenous base, many used as drugs; e.g. morphine, quinine, strychnine.
alternate
(as adjective) leaves or flowers borne singly at different levels along a stem includes spiralled parts; or (as verb) when something occurs between something else, for example stamens alternating with petals; compare opposite.
amphitropous
When the ovule is bent so that both ends are near each other; cf. anatropous, campylotropous, orthotropous.
amplexicaul
With the base dilated and clasping the stem, usually of leaves.
anastomosing
When veins are joined by cross-veins to form a network.
anatropous
When an ovule is inverted so that the micropyle faces the placenta (this is the most common ovule orientation in flowering plants); cf. amphitropous, campylotropous, orthotropous.
androdioecious
Of plants, having bisexual flowers and male flowers on separate individuals; cf. andromonoecious, polygamodioecious, polygamomonoecious, polygamous.
andromonoecious
of a species, with bisexual flowers and male flowers on the same plant; cf. gynomonoecious
androecium
Male parts of flower; the stamens of a flower collectively; cf. gynoecium. Abbreviation: A. For instance A 3+3 indicates 6 stamens in two whorls.
androgynophore
A stalk bearing both the androecium and gynoecium of a flower above the level of insertion of the perianth.
androgynous
With male and female flowers in the same inflorescence.
andromonoecious
Of plants, having bisexual and male flowers on the same individual; cf. andromonoecious, polygamodioecious, polygamomonoecious, polygamous.
Anemophily
Pollination by wind.
angiosperms
'flowering plants'; plants with developing seeds enclosed in an ovary.
anisomery
the condition of having a floral whorl with a different (usually smaller) number of parts from the other floral whorls.
annual
A plant that completes its life cycle and dies within one year.
anterior
Away from the axis; usually abaxial.
anther
Pollen-bearing part of the stamen.
anthesis
Time of flowering; the stage at which the pollen is released from the anthers inside the bud onto the pollen presenter, usually corresponding with flower opening.
antrorse
Directed towards or upwards, e.g. of hairs on a stem; cf. retrorse.
apetalous
Without petals.
apex
(plural apices) The tip; the point furthest from the point of attachment.
apiculate
(Usually referring to a leaf) terminating in a short sharp flexible point; less abrupt than mucronate.
apocarpous
Of a gynoecium consisting with one or more carpels which are free from one another (or almost so); e.g. Ranunculaceae, Dilleniaceae.
apomixis
Reproduction, where viable seed or spores are produced without fertilization. A plant produced in this way is an apomict.
appendage
A secondary part attached to the main structure; an external growth that seldom has any obvious function.
appressed
Pressed closely, but not fused; e.g. leaves against a stem.
aquatic
Plants whose natural habitat is water: living in or on water for all or a substantial part of the organism's life span, generally restricted to fresh or inland waters.
arachnoid
Cobwebby, from being covered with fine white hairs.
arborescent
Tree-like in growth or general appearance.
arboretum
(plural arboreta) A taxonomically arranged collection of trees.
archaeophyte
An non-native plant that has been present in a geographic area for some time; cf. neophyte.
areole
(from areola) A space between the threads of a net; e.g. that part of a leaf surface defined by each of the elements of a vein network; as with cacti, the area between the veinlets of a leaf or the region of a cactus bearing the flowers and/or spines.
aril
(adjective arillate): A membranous or fleshy appendage (formed by expansion of the funicle) which partly or wholly covers a seed; e.g. the fleshy outer layer of lychee fruit and as found in Sapindaceae.
aristate
With a stiff, bristle-like awn or tip.
article
A segment of a jointed stem or of a fruit with constrictions between the seeds; an organ part that separates easily from the rest of the organ at a joint or articulation.
articulate
Jointed; separating freely, leaving a clean scar; for example the fronds of certain ferns where they join the rhizome.
ascending
Spreading horizontally, then becoming erect.
asexual
Of reproduction that does not involve the gametes; i.e. vegetative reproduction.
attenuate
Narrowing gradually.
auricle
(adjective auriculate): Ear-shaped lobe.
awn
Fine bristle-like appendage; e.g. terminating or on the back of glumes and/or lemmas of some grass spikelets.
axil
The upper angle between one part of a plant and another; e.g. the stem and a leaf.
axile
On an axis; of a placenta, on the central axis of the ovary.
axillary
Borne in or arising from the axil of a leaf.
axis
A line passing through the centre of something; it usually refers to the main stem of a whole plant or inflorescence.

B[edit]

bark
the protective external layer of tissue on the stems and roots of trees and shrubs; includes all of the living and non-living tissue external to the cambium.
basal
at the base, situated or attached at the base.
basifixed
something attached by its base; e.g. an anther attached to the filament.
basipetal
developing sequentially from the apex towards the base (i.e. with the youngest towards the base); e.g. of flowers in an inflorescence. Also, moving from leaves to roots, e.g. of molecular signals in plants.
bathyphyll
a specialized leaf that is produced at the base of a plant, usually when the plant is immature, and which serves to anchor the plant to a substrate; especially notable in the fern Teratophyllum. (compare: acrophyll).
beak
a prominent pointed terminal projection, especially of a carpel or fruit. adj. beaked
berry
an indehiscent fruit, with the seeds immersed in the pulp, for instance tomato.
biennial
plant which completes its life cycle and dies within the second year; usually also forms a basal rosette of leaves the first year and flowers and fruits the second year.
bifid
forked; cut in two for about half its length. See also trifid.
bifoliate
having 2 leaflets (referring to a compound leaf).
bilabiate
having two lips; e.g. the form of the petals in many irregular flowers.
bilateral
arranged on opposite sides; e.g. leaves on a stem.
biloculate
having two loculi; e.g. in the anthers.
binomial
making use of names consisting of two words to form the scientific name (or combination) in a Latin form. For example, where the first is the name of the genus to which the species belongs, and the second is the epithet given to that species to distinguish it from others in the same genus.
binomial nomenclature
the system of nomenclature in which the scientific name of a species (and not of a taxon at any other rank) is a combination of two names, the first name being the generic name. The second name is referred to botanically as the specific epithet. Note that the two names constitute the species name, not just the second word.
bipinnate
twice pinnate; for example of a compound leaf with individual leaflets pinnately divided.
bipinnatisect
a pinnatisect leaf with deeply dissected segments.
bisexual
bearing both male and female reproductive organs; usually, flowers with both stamens and carpels; hermaphrodite. See Sexual reproduction in plants.
bitegmic
(of an ovule), covered by two integuments.
bivalve
having two valves or hinged parts. See also trivalve.
blade
the lamina or flattened part of a leaf, excluding the stalk.
bloom
a fine white or bluish waxy powder occurring on plant parts, usually stems, leaves and fruits. It is easily removed by rubbing.
bole
the trunk of a tree, usually below the lowest branch; cf. canopy.
bract
modified leaf associated with flower or inflorescence, differing in shape, size or colour from other leaves (and without an axillary bud).
bracteate
possessing bracts.
bracteole
small bracts borne singly or in pairs on the pedicel or calyx.
bracteolate
possessing bracteoles (bractlets)
bractlet
bracteole
branchlet
a small branch.
bristle
(adjective: bristly) straight stiff hair (smooth or with minute teeth) or upper part of an awn (when the latter is bent and has a lower, stouter, and usually twisted part, called the column).
bryophyte
a botanical group including mosses and liverworts. Technically a classification of plants including three classes: hornworts (Anthocerotae), liverworts (Hepaticae) and mosses (Musci).
bulb
thick storage organ, usually underground, consisting of a stem and leaf bases (the inner ones fleshy).
bulbel
a bulb arising from another bulb.
bulbil
small deciduous bulb or tuber formed in the axil of a leaf or pinna; a means of vegetative propagation.
bulblet
a bulb arising from another bulb; a bulbil.
bullate
surface with rounded or globular blisters.
burr
loosely, a prickly fruit; a rough or prickly propagule consisting of a seed or fruit and associated floral parts or bracts.
buttress root
a root growing from the above-ground stem or trunk, and providing support, as in the case of Ficus macrophylla, the Moreton Bay Fig.

C[edit]

caducous
falling off early, for example the sepals of poppies, that fall off when the petals begin to open; compare persistent and fugacious.
caespitose
tufted; e.g. the growth form of some grasses.
callus
(plural calli) generally, a protruding mass of tissue; in orchids, fleshy outgrowths from the labellum which can be variously shaped from papillae to plates; in grasses, hardened extension from the base of a floret (formed from the rachilla joint and/or the base of the lemma) which may or may not elongate and is often covered in hairs or bristles.
calycophyll
a leaf-like structure formed from a sepal or calyx lobe which enlarges, usually many-fold, before or after anthesis, especially when most of the sepals or calyx lobes retain their original size. More extreme than an accrescent calyx, calycophylls are found in Rubiaceae. cf. semaphyll, pterophyll.
calyculate
having an epicalyx.
calyculus
(1) a cup-shaped structure formed from bracts, (2) in some Asteraceae, a circle of bracts below the involucre.
calyptra
a hood or lid; see operculum.
calyx
(plural calyces) the outer whorl of a flower, usually green; the sepals of one flower collectively.
calyx tube
a tube formed by the fusion of the sepals (calyx), at least at the base.
campanulate
bell-shaped.
campylotropous
when the ovule is oriented transversely (i.e. with its axis at right angles to its stalk) and with a curved embyro sac; cf. amphitropous, anatropous, orthotropous.
canaliculate
channelled; with a longitudinal groove.
canescent
approaching white in color, as in a leaf covered with white down or wool.
canopy
the branches and foliage of a tree; crown; cf. trunk.
capillary
1.  (noun) a tube, pore or passage with a narrow internal cross-section.
2.  (adjective) slender, hair-like.
capitate
with knob-like head; of an inflorescence, with the flowers unstalked and aggregated into a dense cluster; of a stigma, like the head of a pin.
capitulum
a dense cluster of sessile, or almost sessile, flowers or florets; a head.
capsule
a dry fruit formed from two of more united carpels and dehiscing when ripe (usually by splitting into pieces or opening at summit by teeth or pores).
carina
(adjective carinate) see keel.
carinal canal
a longitudinal cavity in the stems of Equisetum and extinct Equisetopsida, coinciding with a ridge in the stem surface.
carpel
a female organ borne at the centre of a flower, consisting of an ovary, a style and a stigma. The gynoecium is the collective term for all the carpels of a single flower.
cartilaginous
hard and tough; gristly.
caryopsis
a dry, indehiscent, one-seeded fruit in which the seed coat is closely fused to the fruit wall, as in most grasses.
casual alien
a plant that appears with no apparent human assistance but does not develop a sustained population(s). Plants that persist only by new introductions; cf. alien.
cataphyll
Early leaf forms of plants or shoots, such as cotyledons, bud-scales, rhizome-scales; anatomically they are leaves, but do not develop to perform the usual functions of photosynthetic leaves.
catkin
a spike, usually pendulous, in which the mostly small flowers are unisexual and without a conspicuous perianth; e.g. willows, poplars, oaks and casuarinas. The individual flowers often have scaly bracts; they are generally wind-pollinated. The catkins are usually shed as a unit.
caudate
having a narrow tail-like appendage.
caudex (plural: caudices)
Literally the stem of a plant, but also used to mean a rootstock, or particularly a basal stem structure or storage organ from which new growth arises. See also caudiciform
caudiciform
Literally meaning "stem-like" or "caudex-like", is sometimes used to mean "pachycaul", meaning "thick-stemmed".
cauline
borne on an aerial stem, e.g. leaves, flower or fruits (when applied to the latter two organs, usually referring to older stems; = cauliflorous).
cell
1.  basic (microscopic) unit of plant structure, generally consisting of compartments in a viscous fluid surrounded by a wall.
2.  cavity of an anther or ovary.
centrifixed
of a two-branched organ attached by its centre, e.g. a hair, or anther.
chartaceous
with a papery texture.
chamber
cavity of an ovary.
chasmogamous
of flowers that are pollinated when the perianth is open; cf. cleistogamous.
chimera
an individual composed of two or more genetically different tissues, most commonly as a result of a graft and sometimes within the individual, by mutations and irregularities that occur during cell division.
chiropterophilous
pollinated by bats.
chlorophyll
a green pigment in chloroplasts, essential for photosynthesis.
chloroplast
an organelle present in plant cells that contains chlorophyll.
cilia
(singular cilium, adjective ciliate) generally, hairs more or less confined to the margins of an organ, like eye-lashes; in motile cells, minute, hair-like protrusions which aid motility.
circinate (circinnate)
spirally coiled with the tip innermost; e.g. the developing fronds of most ferns.
cladode
a photosynthetic stem, often leaf-like and usually with foliage leaves either absent or much reduced; cf. phyllode.
class
the principal category for taxa in a rank between division and order.
clathrate
latticed or pierced with apertures. In this structures, such as scales, this appearance is caused by thick cell walls between adjacent cells and thin cell walls on the sides of the cells that face the surfaces of the scale.
clavate
club-shaped.
claw
1.  narrow, stalk-like basal portion of petal, sepal of bract.
2.  in Melaleuca, the united portion of a stamen bundle.
cleistogamous
of flowers that self-pollinate and never open fully, or self-pollinate before opening; cf. chasmogamous.
climber
a plant growing more or less erect by leaning or twining on another structure for support, or by clinging with tendrils.
cline
(adjective clinal) continuous morphological variation in form within a species or sometimes between two species.
clone
plants derived from the vegetative reproduction of an individual, all having the same genetic constitution.
coalescent
plant parts fused or grown together to form a single unit.
cochleariform
concave, spoon-shaped.
cochleate
coiled like a snail's shell.
colleter
a multicellular, glandular hair that usually produces a mucilaginous substance and is located on sepals, stipules, or petioles, or on nearby parts of stems; commonly found on plants in the order Gentianales.
columella
in flowering plants, the central axis of the cone or fruit, e.g. in Callitris.
column
1.  structure extending above ovary and incorporating the style and stamens; gynostemium; e.g. in orchids.
2.  in grasses, the lower, stouter, and usually twisted part of an awn, distinct from the slender upper part or bristle.
columnar
shaped like a column.
commercial name
a name often of no botanical standing and not governed by the ICNCP. The term generally applies to names such as Trademark Names, names covered by Plant Breeders Rights, Patents and Promotional Names; often used to enhance the sale of a plant.
commissure
the seam or face by which two carpels adhere.
community
an assemblage, in nature, of plants that characteristically occur together.
compound
composed of several parts, for instance a leaf with leaflets, a gynoecium with several carpels, or an inflorescence made up of smaller inflorescences.
compressed
flattened lengthwise, either laterally (from side to side) or dorsally (from front to back).
concolorous
the same colour throughout.
cone
a fruit, usually woody, ovoid to globular, including scales, bracts or bracteoles arranged around a central axis, e.g. in gymnosperms, especially conifers and Casuarina.
conflorescence
of an inflorescence when the overall structure substantially differs from that of the individual branches of the inflorescence, a rarely used term; e.g. the bottlebrush multiple-flower head of callistemons.
connate
fused to another organ (or organs) of the same kind; e.g. petals in a floral tube; cf. adnate.
connective
the part of an anther that connects the anther cells.
connivent
coming into contact or converging.
conspecific
belonging to the same species.
contiguous
adjoining, touching, but not united.
contorted
twisted out of the normal shape.
convolute
referring to the arrangement of floral or foliar organs in a bud when each organ or segment has one edge overlapping the adjacent organ or segment; a form of imbricate arrangement; contorted.
cordate
heart-shaped, with the notch lowermost; of the base of a leaf, like the notched part of a heart.
coriaceous
leathery; stiff and tough, but somewhat flexible.
corm
fleshy, swollen stem base, usually underground, storing food reserves, with buds naked or covered by very thin scales; a type of rootstock. Adjectives derived from "corm" include "cormose" and "cormous".
corolla
collective term for the petals of a flower.
corona

(adjective: coronate) literally, crown

1. in flowering plants, ring of tissue arising from the corolla or perianth of a flower and standing between the perianth lobes and the stamens; e.g. the daffodil trumpet, passionfruit.

2.  in grasses, a hardened ring of tissue surmounting the lemma in some species.
corymb
(adjective corymbose) inflorescence with branches arising at different points but reaching about the same height, giving the flower cluster a flat-topped appearance.
costa
(adjective costate) a rib.
costapalmate
a costapalmate leaf has a definite costa (midrib), unlike the typical palmate or fan leaf, but the leaflets are arranged radially like in a palmate leaf.
cotyledon
primary leaf or leaves of an embryo, becoming the seed leaf or leaves.
crenate
with blunt or rounded teeth, scalloped.
crenulate
minutely scalloped.
crisped
finely curled. A term generally applied to the edges of leaves and petals.
crown
see canopy.
cross
to make something interbreed; the act of hybridization.
cruciform
cross-shaped.
crustaceous
hard, thin and brittle.
cryptogams
ferns, bryophytes, algae and fungi (including lichenized fungi); 'lower plants'; plants producing spores, and without stamens, ovaries or seeds, literally plants whose sexual reproductive organs are not conspicuous cf. phanerogam.
cucullate
from Latin cucullus, a hood. Hood-like or hooded, commonly referring to the shape of leaves or petals. (Example: Pelargonium cucullatum). Similarly derived terms include cuculliform and cuccularis.
culm
in grasses, sedges, rushes, and some other monocotyledons, an aerial stem bearing the inflorescence; strictly, from the base of the plant to the lowest involucral bract (or base of the inflorescence).
cultigen
a plant whose origin or selection is primarily due to intentional human activity.
cultivar
the term cultivar is derived from cultivated variety and denotes an assemblage of cultivated plants clearly distinguished by one or more characters (morphological, physiological, cytological, chemical or other); when reproduced (sexually or asexually), the assemblage retains its distinguishing characters. A cultivar may arise in cultivation or be introduced from the wild. It is a variant of horticultural interest or value. Cultivar names are written with single quotation marks around them e.g. 'Blue Carpet', 'Alba'. All new names established after 1 January 1959, must be in common language (that is, not in Latin) but names established in Latin prior to this date are retained in Latin form.
cultivar epithet
the defining part of a name that denominates a cultivar. Cultivars are designated by fancy (q.v.) epithets appended either to the scientific name or to the common name of the taxon to which they belong; they are not italicized but placed in single quotation marks, for example Rubus nitidoides 'Merton Early'. 'Merton Early' is the cultivar epithet.
cuneate
wedge-shaped; with straight sides converging at base. See Leaf shape.
cupule
a cup-shaped structure composed of coalescent bracts, such as the cup of an acorn.
cupular
shaped like a cupule.
cupulate
bearing cupules.
cupuliform
nearly hemispherical, shaped like a cupola or dome.
cuspidate
tipped with a cusp.
cutting
a piece of plant, usually an apical tip of shoot structure but may be root or leaf, cut from plant and used for vegetative propagation.
cyathium
an inflorescence of unisexual flowers surrounded by involucral bracts, e.g. the flowers of Euphorbia.
cyme
(adjective cymose) inflorescence in which the main axis and all lateral branches end in a flower (each lateral may be repeatedly branched).
cypsela
a dry, indehiscent, one-seeded fruit formed from an inferior ovary.

D[edit]

deciduous
falling seasonally, for instance bark, leaves, petals; compare persistent.
declinate
curving downwards, and then upwards at the tip. May be qualified, e.g. declinate-ascendant
decompound
divided to more than one level, as in bipinnate leaves for example, in which the leaflets of what otherwise would be a pinnate leaf, are themselves pinnately divided
decorticate
to shed or peel off the outer bark of a tree.
decumbent
with branches growing horizontally but turned up at the ends.
decurrent
extending downwards beyond the point of exsertion, e.g. when the base of a leaf is prolonged downwards along the stem in a raised line or narrow wing.
decussant
= decussate. The usage decussant is questionable and occurs rarely, probably as an error. The formally correct usage is decussate.
decussate
opposite, with successive pairs borne at right angles to the last; generally applied to the arrangement of leaves.
definite
of a constant number; e.g. twice as many stamens as the petals or sepals (or less), or an inflorescence ending in a flower or an aborted floral bud, typically a cymose inflorescence; cf. indefinite.
deflexed
bent downwards; compare inflexed.
dehiscent
breaking open at maturity to release contents. Generally refers to the release of seed from some fruits; also pollen from anthers.
deltoid
with the shape of the uppercase Greek letter Δ, i.e. like a more or less equilateral triangle. See Leaf shape.
dendroid
tree-like, branching like a tree.
dentate
toothed. See Leaf margin.
denticulate
finely toothed, a diminutive form of dentate.
determinate
limited, usually in growth.
diaspore
A reproductive part of a plant, adapted for dispersal and for establishing new plants; a disseminule such as a seed, or specialised buds, branches, inflorescences or fruits.
dichasium
a cymose inflorescence with all branches below the terminal flower in regular opposite pairs; compare monochasium.
dichlamydeous
perianth is divided into separate calyx and corolla. Compare to homochlamydeous, in which they are indistinguishable
dichotomous
forking into two equal branches, resulting from an equal division of the growing tip. Typically refers to mode of branch growth, as in Aloe dichotoma, but also to other organs, such as the thorns of various species of Carissa (which morphologically are branches) and thalli or hyphae of various algae and fungi.
dicotyledon
a flowering plant whose embryo has two (rarely more) cotyledons (seed leaves) (common usage: dicot.) compare monocotyledon (common usage: monocot.).
digitate
with segments spreading from a common centre, like the fingers of a hand; see also palmatisect.
dimorphic (dimorphous, dimorphism)
of 2 different kinds (in respect to shape and/or size), for example of stamens, fronds, leaves. See also monomorphic (having a single form) and polymorphic (many forms)
dioecious
of plant, when male and female reproductive structures develop on different individuals; of infloresence, male and female flowers in separate infloresences; cf. monoecious.
diploid
with two full sets of chromosomes in the nucleus of a cell; having two complements of haploid chromosomes, that is the two complete sets of chromosomes, one from each of the parental gamete. This is expressed symbolically as 2n, where n = the gamete number of chromosomes.
diplostemonous
stamens arranged in two whorls, with the outer whorl alternating with the petals, while the inner whorl is opposite the petals. Compare: obdiplostemonous.
disk (disc)
a plate or ring of structures derived from the receptacle, and occurring between whorls of floral parts: in daisies, the central part of capitulum, hence disk flowers or florets.
discoid
resembling a disc or plate, having both thickness and parallel faces and with a rounded margin. Also used to describe the flower head of Compositae where there are no ray florets, but only disc florets.
discolorous
of leaves, with upper and lower surfaces of a different colour.
disjunct
occurring in widely separated geographic areas, distinctly separate; applies to a discontinuous range in which one or more populations are separated from other potentially interbreeding populations far enough as to preclude gene flow between them.
dissected
deeply divided; cut into many segments.
distal
remote from the point of origin or attachment; the free end; cf. proximal.
distichous
arranged in two opposite rows (and hence in the same plane).
distinct
separate or free, not united.
diurnal
of the day; occurring or opening in the daytime.
divaricate
wide-spreading.
divergent
spreading in different directions, generally upward.
division
the term used for the rank below kingdom in the taxonomic hierarchy.
Leaves of Epipremnum pinnatum have a drip tip
domatia
pits formed at the junction of two veins on the undersurface of leaves (mostly of rainforest plants); often modified appendages that shelter parasites and other micro-organisms.
dorsal
the back; at the back; in particular, away from the axis in a lateral organ or away from the substratum in a prostrate plant.
dorsifixed
attached at or by the back, e.g. anthers on a filament.
dorsiventral
having structurally different upper and lower surfaces, e.g. some leaves.
drip tip
a long narrow extension at the apex of a leaf or leaflet.
drupe
a succulent fruit formed from one carpel; the single seed is enclosed by a stony layer of the fruit wall; kernel; e.g. peaches, olives and the fruit of Nitraria billardieri.

E[edit]

ebracteate
without bracts. Similarly ebracteolate.
ecological amplitude
the range of environmental conditions in which an organism can survive.
elaisome
oily body attached to the seed.
ellipsoid
a 3-dimensional shape, elliptical in all sections through the long-axis.
elliptical (elliptic)
planar, shaped like a flattened circle, symmetrical about both the long and the short axis; about twice as long as broad, tapering equally both to the tip and the base; oval.
emarginate
notched at apex (notch usually broad and shallow).
embryo
young plant contained by a seed.
enantiostyly
the condition in which the gynoecium protrudes laterally, to the right (dextrostyly) or to the left (sinistrostyly) of the androecium. example: Senna.
endemic
having a natural distribution restricted to a particular geographic region; cf. native.
endocarp
the innermost layer of the wall of a fruit; in a drupe, the stony layer surrounding the seed.
endosperm
nutritive tissue in a seed; albumen.
ensiform
shaped like the blade of a sword.
entire
1.  not divided.
2.  (of a margin) having a smooth margin, not lobed or toothed (it may be wavy or scalloped).
ephemeral
short-lived.
The enlarged calyx and smaller epicalyx of Hibiscus sabdariffa
epicalyx
an involucre resembling an outer calyx; e.g. as seen in Hibiscus.
epicarp
the outer layer of the wall of a fruit, i.e. the 'skin'.
epicormic
said of buds shoots or flowers developing from the old wood of trees, especially after injury or fire.
epicotyl
the part of the plant axis or stem between the cotyledonary node and first foliage leaves.
epidermis
an organ's outermost layer of cells, usually only one cell thick.
epigynous
borne on the ovary; describes floral parts when attached above the level of the ovary and arising from tissue fused to the ovary wall; cf. hypogynous, perigynous.
An epilithic lichen
epilithic
growing on stone; compare lithophytic, a plant growing on stone.
epipetalous
of stamens that are attached to the petals.
epiphytic
see lithophytic.
epitepalous
of stamens that are attached to the tepals.
epiphyte
(adjective epiphytic) one plant growing on another without deriving nourishment from it (in other words, not parasitic); compare parasite. Loosely, and incorrectly, applied to plants that are not terrestrial (they may grown on various inorganic or organic surfaces), and often to orchids, which are rock-dwelling (and therefore strictly lithophytic).
epithet
the adjectival component in a binomial; final word or combination of words in a name of more than one word (other than a term denoting rank) that denominates an individual taxon.
equitant
of a leaf when folded lengthwise with edges adhering except at the base, where it clasps another leaf on the opposite side of the stem.
erect
upright, more or less perpendicular to the ground or point of attachment.
ericoid
with leaves like the European heath (Erica), small and sharply pointed.
erose
with the margin irregular as though nibbled or worn away.
even-pinnate
having an even number of leaflets in a compound leaf, = paripinnate.
evergreen
not deciduous, having leaves all the year round.
ex
in nomenclature, indicating that the preceding author proposed the name but did not legitimately publish it, and that the succeeding author referred to the first author when legitimately publishing the name. See Author citation (botany).
exocarp
the outer layer of the pericarp, often the skin of fleshy fruits.
exotesta
the outer layer of the testa (seed coat). It is derived from the outer integument of the ovule.
exotic
not native; introduced from another region or country.
exserted
projected beyond, e.g. the stamens beyond the corolla tube.
exstipulate
without stipules.
extrastaminal
outside the stamens or androecium, usually referring to the location of a nectary disk.
extrorse
of anther locules, opening towards the outside of the flower; cf. introrse, latrorse.

F[edit]

F1 hybrid
a single cross; a plant breeding term for the result of a repeatable cross between two pure bred lines.
F2 hybrid
a plant breeding term for the result of a plant arising from a cross between two F1 hybrids; may also refer to self-pollination in a population of F1 hybrids.
facultative
of parasites, optional; compare obligate.
falcate
curved like the blade of a scythe.
family
a formal group of one or more genera with features and/or ancestry in common; the term for the principal rank between order and genus.
fascicle
(adjective fasciculate) cluster, e.g. a tuft of leaves all arising from the same node.
fastigiate
parallel, clustered and erect, e.g. the arrangement of branches in the Lombardy Poplar.
felted
covered with very dense, interlocked and matted hairs with the appearance or texture of felt or woollen cloth.
ferruginous
rust-colored.
fertile
capable of producing fruit; of flowers when they produce seed or of anthers containing pollen.
fertilization
union of male and female gametes.
filament
1.  stalk of a stamen
2.  thread, one or a few cells thick.
filamentous
consisting of filaments or fibres.
filiform
thread-like. See Leaf shapes.
fimbria
slender hair-like process (plural: fimbriae)
fimbriate
fringed.
fissure
a split or crack, often referring to fissured bark. also, a line or opening of dehiscence.
flabellate
fan-shaped.
flaccid
limp; tending to wilt; compare turgid.
flexuous (flexuose)
bent alternately in different directions; zig-zag.
floccose
with a soft and woolly covering of hairs.
flora
1.  all the plants growing in a certain region or country.
2.  an enumeration of them, generally with a guide to their identification (e.g. the present volume, the Flora of Victoria, the Flora of New South Wales and so on). In this case 'flora' is written with a capital F.
floral leaves
the upper leaves at the base of the flowering branches.
floral tube
tube bearing the perianth and stamens, consisting of tissue derived from the receptacle and/or perianth and/or stamens; hypanthium.
floret
literally a small flower, but usually refers to the individual true flowers clustered within an inflorescence, particularly in inflorescences of the daisy and grass families.
flower
the sexual reproductive structure of the angiosperms, typically with a gynoecium, androecium, perianth and an axis.
follicle
a dry fruit formed from one carpel, splitting along a single suture, to which the seeds are attached; cf. pod (of legume).
forb
any non-woody flowering plant that is not a grass, sedge, or rush.
forest
vegetation dominated by trees with single trunks (including closely arranged trees with or without an understorey of shrubs and herbs).
forma (in common usage, form)
a taxonomic category subordinate to species and within the taxonomic hierarchy, below variety (varietas), usually differentiated by a minor character.
free
not united with others organs of the same type; not attached at one end.
free central
of placentation, ovules attached to a free-standing column in the centre of a unilocular ovary.
frond
a leaf of a fern, cycad or palm.
fruit
seed-bearing structure in angiosperms formed from the ovary, and sometimes associated floral parts, after flowering.
fugacious
disappearing, falling off, or withering; compare persistent and caducous.
funicle (funiculus)
the stalk of an ovule.
funnelform
with a form gradually widening from the base to apex; funnel-shaped.
fused
joined together.
fusiform
3-dimensional, narrowing gradually from the middle towards each end; spindle-shaped.

G[edit]

galbulus
(in gymnosperms) a fleshy cone (megastrobilus); chiefly relates to those borne by junipers and cypresses and often mistakenly called berries.
gamete
(in ferns, gymnosperms and angiosperms) a cell or nucleus that fuses with another of the opposite sex in sexual reproduction.
gametophyte
plant that bears gametes; in ferns, usually a small but discrete plant very different from the sporophyte (which is normally considered the fern plant); in gymnosperms and angiosperms, a microscopic structure (part of the reproductive apparatus) not recognizable as a discrete plant.
gene pool
the range of genetic variation found in a population.
genus
(plural genera) a group of one or more species with features or ancestry (or both) in common. Genus is the principal category of taxa intermediate in rank between family and species in the nomenclatural hierarchy.
generic name
the name of a genus, for example Acacia, Eucalyptus.
genotype
the genetic make-up of an individual.
germination
1.  of seeds, describing the complex sequence of physiological and structural changes that occur from resting to growth stage.
2.  of a pollen grain; production of a pollen tube when contacting a stigma receptive to it.
3.  of a spore of fungi/bacterium; change of state – from resting to vegetative.
gibbous (gibbose)
when part of an organ is swollen; usually with a pouch-like enlargement at base.
glabrescent
becoming glabrous, almost glabrous.
glabrous
without surface ornamentation such as hairs, scales or bristles.
gland
a secretory structure within or on the surface of a plant; (loosely) a smooth, usually shining, bead-like outgrowth.
glandular hair
hairs tipped with a gland.
glaucous
with a whitish bloom, blue-green in colour; e.g. the surface of the young leaves of many eucalypts.
globose (globular)
spherical. See also subglobose.
globulose
small or nearly spherical.
glochid
a barbed hair or bristle, e.g. the fine hairs in Opuntia.
glumes
bracts subtending the floret(s) of a sedge, or similar plant; in grasses forming the lowermost organs of a spikelet (there are usually 2 but 1 is sometimes reduced; or rarely, both are absent).
glutinous
sticky.
graft
1.  of a plant, the artificial union of plant parts.
2.  a plant shoot suitable for grafting; loosely means a scion, sucker, or branch.
3.  an old word for a spade's depth of soil.
4.  a kind of spade used for digging drains.
graft chimaera (sometimes graft hybrid)
a taxon whose members consist of tissue from two or more different plants in intimate association originated by grafting. The addition sign "+" is used to indicate a graft-chimaera either as a part of a formula (e.g. Crataegus monogyna + Mespilus germanica), or in front of an abbreviated name (e.g. +Crataegomespilus 'Dardari'). The nomenclature of graft hybrids is governed by the International Code of Nomenclature for Cultivated Plants.
granular
of a surface, covered with small rounded protuberances.
grass
a plant belonging to the family Poaceae.
grassland
low vegetation dominated by grasses.
groundcover
1.  of a plant, with a very flat and soil-hugging habit.
2.  a term applied to describe a plant that covers the soil surface so densely that it smothers all beneath it.
Group

a formal category equivalent to or below the rank of genus. It distinguishes:

1. an assemblage of two or more cultivars within a species or hybrid.

2.  plants derived from a hybrid in which one or more of the parent species is not known or is of uncertain origin.
3.  a range of cultivated plants of a species or hybrid which may exhibit variation but share one or more characters, which makes it worth distinguishing them as a unit.
Guard cell
each of the two cells that surround the stoma and allow gas exchange from the apoplast of the plant to the external air.
gymnosperm
a seed-bearing plant with ovules borne on the surface of a sporophyll; includes, among others, conifers, Ginkgo, Gnetum and cycads.
gynobasic
of a style, arising near the base of the gynoecium, e.g. between the lobes of the ovary.
gynodioecious
of a species, with some plants bearing only bisexual flowers and others bearing only female flowers.
gynomonoecious
of a species, with bisexual flowers and female flowers on the same plant.
gynoecium
female parts of flower; the collective term for the carpels of a flower whether united or free; cf. pistil; androecium. Abbreviation: G. For instance G indicating superior ovary. G(5) indicates having 5 fused carpels.
gynophore
stalk supporting the gynoecium (above the level of insertion of the other floral parts).

H[edit]

habit
the general external appearance of a plant, including size, shape, texture and orientation.
habitat
the place where a plant lives; the environmental conditions of its home.
hair
a single elongated cell or row of cells borne on the surface of an organ.
half-inferior
of ovary, partly below and partly above the level of attachment of the other floral parts; compare inferior, superior.
halophyte
a plant adapted to living in highly saline habitats; a plant that accumulates high concentrations of salt in its tissues.
hand-pollination
the controlled act of pollination that excludes the possibility of open-pollination.
haploid
of chromosomes, and relative to the phase of an alternation of generations in which the duplicated chromosome set or diploid condition is reduced; the condition when the chromosomes are not duplicated, e.g. the complement of chromosomes in the nucleus of a gamete; a single basic set of chromosomes in the nucleus of a cell. This may be expressed symbolically as n, where n = the gamete number of chromosomes.
hastate
like the head of a halbert, i.e. narrow and pointed but abruptly enlarged at the base into two acute diverging lobes; may refer only to the base of a leaf with such lobes; cf. sagittate.
haustorium
in parasitic plants, a structure developed for penetrating the host's tissues.
see capitulum.
heathland
vegetation dominated by small shrubs which usually have ericoid leaves.
helicoid
coiled; of a cymose inflorescence, when the branching is repeatedly on the same side (the apex is often recurved); cf. scorpioid.
herb
a vascular plant that does not develop a woody stem; e.g. a violet.
herbaceous
not woody; usually green, and soft in texture.
herbarium
a collection of preserved, usually dried, plant material. Also a building in which such collections are stored.
hermaphrodite
see bisexual.
heteroblastic
having parts, especially leaves, that are distinctly different between the juvenile and adult stages.
heteromorphic
of 2 or more distinct morphologies (e.g. of different size and shape).
hilum
the scar on a seed coat where it separates from its stalk (funicle).
hip
the fruit of a rose.
hippocrepiform
horseshoe-shaped.
hirsute
bearing coarse, rough, longish hairs. See Indumentum.
hispid
having long erect rigid hairs or bristles, harsh to touch.
hoary
covered with a greyish to whitish layer of very short, closely interwoven hairs, giving a frosted appearance.
holotype
a type chosen by the author of a name; cf. a lectotype, which is chosen by a later author.
homochlamydeous
perianth not divided into calyx and corolla. Compare to dichlamydeous, in which they are separate
hort.

(never capiltalised) of gardens, an author citation used in two ways:

as a name misapplied by gardeners

2.  as an invalid name derived from horticultural writings of confused authorship.
A hypocarpium forms below the fruits of Sassafras albidum
hyaline
translucent; usually delicately membranous and colourless.
hybrid
a plant produced by the crossing of parents belonging to two different named groups, e.g. genera, species, varieties, subspecies, forma and so on; i.e. the progeny resulting within and between two different plants. An F1 hybrid is the primary product of such a cross. An F2 hybrid is a plant arising from a cross between two F1 hybrids (or from the self-pollination of an F1 hybrid).
hybrid formula
the names of the parents of a hybrid joined by a multiplication sign, e.g. Cytisus ardonoi × C. purgans.
Hydrophily
a fairly uncommon form of pollination whereby pollen is distributed by the flow of waters.
hypanthium
see floral tube.
hypogynous
borne below the ovary; used to describe floral parts inserted below the ovary's level of insertion; cf. epigynous, perigynous.
hypocotyl
of an embryo or seedling, the part of the plant axis below the cotyledon and node, but above the root. It marks the transition from root to stem development.
hypocarpium
an enlarged fleshy structure that forms below the fruit, from the receptacle or hypanthium.
hysteranthous
develop after flowering.

I[edit]

idioblast
a cell, especially of a leaf, differing markedly from surrounding cells. They often synthesise specialised products such as crystals.
illegitimate name (nomen illeg.)
a name not abiding by the rules of the botanical Codes, e.g. later homonyms, cultivars that have been Latinised after 1 Jan 1959; cultivar names with more than 10 syllables or 30 letters; cultivar names that use confusing names of other plants, e.g. Camellia 'Rose'.
imbricate
overlapping each other; of perianth parts, edges overlapping in the bud (the convoluted arrangement is a special form of imbrication).
imparipinnate
a pinnate leaf with an odd number of pinnae (terminated by a single leaflet); compare paripinnate.
in
in nomenclature, where the preceding author published the name in an article or book, authored or edited by the succeeding author.
inbreeding
the production of offspring between closely related parents leading to a high degree of similarity; self-fertilization is the most intense form of inbreeding.
incised
cut deeply and (usually) unevenly (a condition intermediate between toothed and lobed).
included
enclosed, not protruding; for example stamens within the corolla.
incurved
bent or curved inwards; of leaf margins, when curved towards the adaxial side.
ined.
abbreviation of Latin inedita, an unpublished work. Used to indicate that a botanical name appeared only in a manuscript that was not published, so the name is invalid.
indefinite
variable in number; numerous; e.g. more than twice as many stamens as petals or sepals, or when an inflorescence is not terminated by a flower (and continues growing); cf. definite.
indehiscent
not opening in any definite manner at maturity; usually referring to fruit.
indeterminate
unlimited, usually in growth.
indigenous
native to the area, not introduced, and not necessarily confined to the region discussed or present throughout it (hardly distinct from ‘native’ but usually applied to a smaller area). For example, the Cootamundra Wattle is native to Australia but indigenous to the Cootamundra region of southern New South Wales; cf. endemic.
indumentum
a collective term for a surface covering of any kind of trichomes, e.g. hairs, scales.
indusium
1.  a membrane covering the sporangia of some ferns.
2.  a cup enclosing the stigma in Goodeniaceae.
inferior
of an ovary, at least partly below the level of attachment of other floral parts; compare superior.
inflated
swollen, like a bladder.
inflexed
bent sharply upwards or forwards; compare deflexed.
inflorescence
several flowers closely grouped together to form an efficient structured unit; the grouping or arrangement of flowers on a plant.
infraspecific
denotes taxonomic ranks below species level, for example subspecies.
infructescence
the grouping or arrangement of fruits on a plant.
infundibular (infundibularform)
funnel-shaped, for example in the corolla of a flower..
inrolled
rolled inwards.
insectivorous
catching, and drawing nutriment from, insects.
Stamens of Calotropis gigantea are inserted at the base of the corolla.
inserted
growing out from
integument
in general, any covering, but especially the covering of an ovule.
intercalary
(of growth) occurring between the apex and the base of an organ
intercalary meristem
a meristem located between the apex and the base of an organ
interjugary glands
in pinnate leaves, glands occurring along the leaf rachis between the pinnae (occurring below the single, and often slightly larger, gland at or just below the insertion of the pinnae); cf. jugary.
internode
the portion of a stem between two nodes.
interpetiolar
of stipules, between the petioles of opposite leaves.
intramarginal
inside but close to the margin, for example a vein in a leaf.
intrastaminal
inside the stamens or androecium, usually referring to the location of a nectary disk.
introrse
of anther locules, with opening towards the centre of flower (at least in bud); cf. extrorse, latrorse.
invalid
use of names not validly published according to the Code; i.e. they are not strictly 'names' in the sense of the International Code of Botanical Nomenclature.
involucre
a group of bracts surrounding the base of a flowerhead; e.g. as seen in a daisy.
involute
rolled inwards, for example when the margins of a leaf are rolled towards the adaxial (usually upper) surface; compare revolute.
irregular
cannot be divided into two equal halves through any vertical plane; compare zygomorphic, actinomorphic, regular.
isobifacial
(of flat structures, especially leaves) with both surfaces similar, usually referring to cell types or to the number and distribution of stomata.
isomerous
Having an equal number of parts in the whorls.


J[edit]

joint
a node or junction of two parts; articulation.
jugary
of glands, gland occurring on the rachis of a bipinnate leaf at the junction or attachment of pairs of pinnae or pinnules, as in some Acacia species; cf. interjugary.
juvenile leaves
formed on a young plant and different in form from the adult leaves.

K[edit]

keel
a ridge like the keel of a boat, e.g. the structure formed by the fusion of the two anterior petals of a flower in the Fabaceae.
kernel
see drupe.
kingdom
the highest generally employed category of the taxonomic hierarchy, above that of division (phylum).

L[edit]

labellum
lip; one of three or five petals which is (usually) different from the others, e.g. in Orchidaceae and Stylidiaceae.
labiate
lipped; where the limb of a corolla is divided into two parts, called an upper and lower lip, the two resembling an open mouth with lips.
lacerate
jagged, as if torn.
laciniate
slashed into narrow, pointed lobes.
lamella
(plural lamellae, adjective lamellate) a thin, plate-like layer.
lamina
the blade of a leaf or the expanded upper part of a petal, sepal or bract.
lanceolate
about four times as long as broad, broadest in the lower half and tapering to the tip; narrowly ovate (sometimes, and incorrectly, used to mean narrowly elliptic; like a lance head).
lateral
attached to the side of an organ, e.g. leaves on a stem.
latex
a milky substance that exudes from such plants such as milk thistles, figs and dandelions.
laticiferous
latex-bearing, producing a milky juice.
latrorse
a type of anther dehiscence in which the anthers open laterally toward adjacent anthers. cf. introrse, extrorse.
lauroid
resembling Laurus, the laurel genus, particularly its leaves.
lax
loose, not compact.
leaf
an outgrowth of a stem, usually flat and green; its main function is food manufacture by photosynthesis. Abbreviation: lvs.
leaf gap
a parenchymatous area in the stele above (distal to) a leaf trace.
leaf trace
a vascular strand connecting the stele to a leaf.
leaflets
the ultimate segments of a compound leaf.
legume
1.  a fruit characteristic of the families Mimosaceae, Caesalpiniaceae and Fabaceae, formed from one carpel and either dihiscent along both sides, or indehiscent.
2.  a crop species in the family Fabaceae.
3.  a plant belonging to the Leguminosae (Fabaceae family).
lemma
the lower of 2 bracts enclosing a grass flower.
lenticel
a loosely packed mass of cells in the bark of a woody plant (used for gas exchange), visible on the surface as a raised powdery spot.
lepidote
covered with small scurfy scales.
liana
a woody climbing plant, rooted in the ground (both liane and liana are used).
liane
a woody climbing plant, rooted in the ground.
ligneous
woody
lignotuber
a woody swelling of the stem below or just above the ground; contains adventitious buds from which new shoots can develop, e.g. after fire.
ligulate
1.  bearing a ligule.
2.  strap-shaped.
ligule
1.  small membranous appendage on the top of the sheath of grass leaves.
2.  a minute adaxial appendage near the base of a leaf, e.g. in Selaginella.
3.  extended, strap-like corolla of some daisy florets.
linear
very narrow in relation to its length, with the sides mostly parallel. See Leaf shape.
lithophytic
a plant growing on rocks; an epilithic plant.
lobe
part of a leaf (or other organ), often rounded, formed by incisions to about halfway to the midrib.
loculicidal
of a fruit, when it dehisces through the centres of loculi; cf. septicidal.
loculus
a chamber or cavity, for example, within an ovary or anther.
lomentum
a pod-like indehiscent fruit that develops constrictions between the segments and at maturity breaks into one-seeded segments.
lunate
crescent-shaped.
lyrate
lyre-shaped; deeply lobed, with a large terminal lobe and smaller lateral ones.

M[edit]

Macaronesia
a biogeographic area encompassing the islands off the coast of NW Africa and Europe, including the Azores, Canaries, Cape Verde Islands and Madeira.
Malaysia
Malay peninsula and North Borneo.
Malesia
a biogeographic region comprising Malaysia, Indonesia, New Guinea, and the Philippines.
mallee
growth habit in which several woody stems arise separately from a lignotuber; a plant with such a growth habit; vegetation characterized by such plants.
mangrove
a shrub or small tree growing in salt or brackish water, usually characterized by pneumatophores.
margin
the edge, as in the edge of a leaf blade.
marginal
occurring at or very close to the margin.
marsh
a waterlogged area; swamp.
mast
the edible vegetative or reproductive part produced by woody species of plants, i.e. trees and shrubs, that wildlife species and some domestic animals consume.
mealy
covered with coarse, floury powder, sometimes due to collapsed hairs.
megaspore
the larger of two kinds of spores produced by a heterosporous plant giving rise to the female gametophyte; compare microspore.
megastrobilus
the larger of two kinds of cones or strobili produced by gymnosperms, being female and producing the seeds; compare microstrobilus.
membranous
thin, translucent and flexible, seldom green.
mericarp
one segment of a fruit (a schizocarp) that splits at maturity into units derived from the individual carpels, or a carpel, usually 1-seeded, released by the break-up at maturity of a fruit formed from 2 or more joined carpels.
meristem
an actively dividing tissue.
mesic
moist, avoiding both extremes of drought and wet; pertaining to conditions of moderate moisture or water supply; applied to organisms (vegetation) occupying moist habitats.
mesocarp
the fleshy portion of the wall of a succulent fruit inside the skin and outside the stony layer (if any), surrounding the seed(s); sarcocarp.
mesomorphic
soft and with little fibrous tissue, but not succulent.
mesophyll
1.  mesophyll tissue, photosynthetic tissue of a leaf, the central tissues between the upper and lower epidermis.
2.  in ecology, the blade of a leaf or leaflet that has a surface area 4500–18225 mm2; A plant, or vegetation, that has mesophyll (sized) leaves.
mesophyllous
(of vegetation) of moist habitats and having mostly large and soft leaves.
mesophyte
a plant thriving under intermediate environmental conditions of moderate moisture and temperature, without major seasonal fluctuations.
microspore
the smaller of two kinds of spores produced by a heterosporous plant; compare megaspore.
microstrobilus
the smaller of two kinds of cones or strobili produced by gymnosperms, being male and producing the pollen; compare megastrobilus.
midrib
the central, and usually most prominent, vein of a leaf or leaf-like organ; midvein.
midvein
see midrib.
monad
a single individual that is free from other individuals, not united with them into a group. The term is usually used for pollen to distinguish single grains from tetrads or polyads.
moniliform
resembling a string of beads.
monochasium
a cymose inflorescence with the branches arising singly; cf. dichasium.
monocots
abbreviation of monocotyledons.
monocotyledon
a flowering plant whose embryo has one cotyledon (seed leaf); compare dicotyledon.
monoecious
of vascular plants, where the male and female reproductive structures are in separate flowers but on the same plant; of inflorescence, including unisexual flowers of both sexes; cf. dioecious.
monograph
of a group of plants, a comprehensive treatise presenting an analysis and synthesis of taxonomic knowledge of that taxon; the fullest account possible (at the time) of a family, tribe or genus. It is generally worldwide in scope and evaluates all taxonomic treatments of that taxon including studies of its evolutionary relationships with other related taxa, and cytological, genetic, morphological, palaeobotanical and ecological studies. The term is often incorrectly applied to any systematic work devoted to a single taxon. Compare revision.
monomorphic
of one type, rather than several. See also dimorphic (two types) and polymorphic (many types)
monotypic
containing only one taxon of the next lower rank, e.g. a family with only one genus, or a genus that includes only a single species.
morphology
the shape or form of an organism or part thereof.
mucro
a sharp, short point, generally at the tip of a leaf or the tip of the midrib of a compound leaf. Diminutive: mucronule.[2]
mucronate
terminating in a mucro.
multiple fruit
a cluster of fruits produced from more than one flower and appearing as a single fruit, often on a swollen axis, as in Moraceae; cf. aggregate fruit.
muricate
covered with short hard protuberances.
mutation
an abrupt and inexplicable variation from the norm, such as the doubleness in flowers, changes in colour, or habit of growth.

N[edit]

native
naturally occurring in an area, but not necessarily confined to it; cf. endemic.
natural hybrid
a hybrid taxon produced by chance in the wild.
naturalised
describing a plant, introduced from another region, that grows and reproduces readily in competition with the natural flora.
nectar
a (usually sweet) fluid produced by the flowers of many plants, collected by bees and other insects.
nectary
(adjective nectariferous) a specialized gland that secretes nectar.
neophyte
a plant that was recently introduced to a geographic area; cf. archaeophyte.
nerve
see vein.
New World
the Americas.
node
the part of a stem where leaves or branches arise.
nomen conservandum
(Latin) a name which although, contrary to the rules of nomenclature (usually a later synonym), must be adopted.
nomen illegitimum
(Latin) see illegitimate name, a name that is superfluous at its time of publication either because the taxon to which it was applied already has a name, or because the name has already been applied to another plant.
nomen invalidum
(Latin) a name that is not validly published. (Abbreviation: nom. inval.)
nomen nudum
(Latin) a name not published in accordance with the International Code of Nomenclature for algae, fungi, and plants, usually without a diagnosis or description of the entity to which it applies, and without reference to either; such a name should not be used.
nomenclature
the naming of things; often restricted to the correct use of scientific names in taxonomy; a system that sets out provisions for the formation and use of names.
noxious
of plants, containing harmful or unwholesome qualities. Applied in conjunction with 'weed' to specifically describe a plant which legislation deems harmful to the environment. Each state and territory in Australia has specific legislation governing noxious weeds.
numerous
Stamens are described as numerous when there are more than twice as many as sepals or petals.
nut
a hard, dry, indehiscent fruit, containing only one seed.
nutlet
a small nut, one of the lobes or sections of the mature ovary of some members of the Boraginaceae, Verbenaceae, and Lamiaceae.

O[edit]

ob-
inversely; usually same shape as suffix but attached by the narrower end, for example obcordate, oblanceolate, obovate.
obconic
of a fruit, hypanthium, pistil or calyx structure; an inverted cone shape.
obcordate
of a leaf blade, broad and notched at the tip; heart shaped but attached at the pointed end.
obdiplostemonous
stamens arranged in two whorls, and having twice as many as the petals, the outer whorl being opposite the petals. Compare: diplostemonous.
oblanceolate
a 2-dimensional shape, lanceolate but broadest in the upper third; cf. lanceolate.
obligate
of parasites, unable to survive without the host; compare faculative.
oblique
slanting; of a leaf, larger on one side of the midrib than the other, in other words asymmetrical.
oblong
length a few times greater than width, with sides almost parallel and ends rounded.
obovate
of a leaf, a 2-dimensional shape of which the length is about 1.5 times the width, and widest above the centre.
obsolete
not evident, or at most rudimentary or vestigial.
obtuse
blunt or rounded at the tip or apex; converging edges making an angle of more than 90°; compare acute. See Leaf shape.
Oceania
the islands of the Pacific (sometimes including Australia).
ocrea (ochrea)
a sheath, formed from two stipules, encircling the node in Polygonaceae.
odd-pinnate
(imparipinnate) having an odd number of leaflets in a compound leaf.
oft.
often. Compare usu. and s.t.
Old World
the world known before the discovery of America; essentially Europe and Asia.
olim
formerly, e.g., "olim B", formerly in the Berlin herbarium (Herbarium Berolinense).
ontogeny
the sequence of developmental stages through which an organism passes.
operculum (calyptra)
a lid or cover that becomes detached at maturity, e.g. in Eucalyptus, a cap covering the bud and formed by the fusion or cohesion of perianth parts.
opposite
(as adjective) leaves or flowers borne at the same level but on opposite sides of the axis; or (as verb) when something occurs on the same radius as something else, for example anthers opposite sepals; compare alternate.
opera utique oppressa (plural), and opus utique oppressum (singular)
listed after the botanical name of a plant, or the name of a publication, this indicates that a publication is listed in the International Code of Nomenclature for algae, fungi, and plants as a suppressed work. Botanical names of the specified rank in the publication are considered not validly published (article 34).
orbicular
flat and more or less circular.
order
a group of one or more families sharing common features, ancestry, or both.
ortet
the original single parent plant from which a clone ultimately derives.
orthotropous
when an ovule is erect, with the micropyle directed away from the placenta; atropous; cf. amphitropous, anatropous, campylotropous.
oval
see elliptical.
ovary
the basal portion of a carpel or group of fused carpels, enclosing the ovule(s).
ovate
shaped like a section through the long-axis of an egg and attached by the wider end.
ovoid
egg-shaped, with wider portion at base; 3-dimensional object, ovate in all sections through long-axis.
ovule
loosely, the seed before fertilization; a structure in a seed plant within which one or more megaspores are formed (after fertilization it develops into a seed).

P[edit]

Senecio articulatus, a pachycladous plant
pachycaul
with a disproportionately thick trunk
pachycladous
with disproportionately thick stems
palea

(plural paleae)

1. the upper of 2 bracts enclosing a grass flower, major contributors to chaff in harvested grain.

2.  Chaffy scales on the receptacles of many Asteraceae.
3.  Chaffy scales on the stipe of many ferns.
paleate
bearing paleae or chaffy scales, as in description of the receptacle of a capitulum of a plant in the Asteraceae.
paleaceous
Chaff-like in texture.
palmate maple leaf (Acer platanoides
compoundly palmate California Buckeye Aesculus californica) leaf
palmate
1.  leaf with veins radiating out from a central point (usually at the top of a petiole), resembling spread out fingers pointing away from the palm.
2.  a compound palmate leaf has leaflets radiate from a central point (usually at the top of a petiole).
palmatifid
deeply divided into several lobes arising from more or less the same level.
palmatisect
intermediate between palmate and palmatifid, i.e. the segments are not fully separated at the base; often more or less digitate.
panicle
(adjective paniculate) a compound raceme; an indeterminate inflorescence in which the flowers are borne on branches of the main axis or on further branches of these.
papilionate
butterfly-like; with a corolla like that of a pea.
papilla
(plural papillae, adjective papillose) a small, elongated protuberance on the surface of an organ, usually an extension of one epidermal cell.
pappus
in daisy florets, a tuft or ring of hairs or scales borne above the ovary and outside the corolla (representing the missing calyx); a tuft of hairs on a fruit.
paraperigonium
Also paraperigone. Anomalous secondary outgrowth of the perianthal meristem with ramifying vasculature. See also perigonium, perianth and corona
[3]
parasite
an organism living on or in a different organism, from which it derives nourishment; compare saprophyte, epiphyte.
parietal
attached to the marginal walls of a structure, for example ovules attached to placentas on the wall of the ovary. See Placentation.
paripinnate
having an even number of leaflets (or pinnae), that is terminated by a pair of pinnae as opposed to a single pinna; compare imparipinnate.
parthenocarpy
the development or production of fruit that is seedless because fertilization never occurred. compare stenospermocarpy.
patent
of plants, spreading.
pauciflor
having few flowers per inflorescence. See also pluriflor.
pectinate
pinnately divided with narrow segments closely set like the teeth of a comb.
pedate
with a terminal lobe or leaflet, and on either side of it an axis curving outwards and backwards, bearing lobe or leaflets on the outer side of the curve.
pedicel
(adjective pedicellate) the stalk of a flower.
peduncle
(adjective pedunculate) the stalk of an inflorescence.
peltate
shield-like; with stalk attached to the lower surface and not to the margin.
pellucid
transmitting light; for example, said of tiny dots in leaves visible when held in front of light.
pendulous
hanging, for example an ovule attached to a placenta on the top of the ovary; compare suspended.
penicillate
tufted like an artist's brush; with long hairs towards one end.
penninervation (penninerved)
with pinnately arranged veins.
pentamerous
in five parts, particularly with respect to flowers, five parts in each whorl. See also trimerous and tetramerous.
pepo
type of berry formed from an inferior ovary and containing many seeds, usually large with a tough outer skin, for instance, pumpkin, cucumber.
perennating
of an organ that survives vegetatively from season to season. A period of reduced activity between seasons is usual.
perennial
a plant whose life span extends over several years.
perfect
of a flower, when bisexual.
perfoliate
with its base wrapped around the stem (so that the stem appears to pass through it), e.g. of leaves and bracts.
perianth
the collective terms for the calyx and corolla of a flower (generally used when the two are similar). Abbreviation: P. For instance P 3+3 indicates the calyx and corolla each have 3 elements, or 3 sepals + 3 petals
pericarp
the wall of a fruit, developed from the ovary wall.
The perigonium of a moss (red in this case), also called a splash cup, surrounds the antheridia and aids in dispersal of sperm
perigonium
1.  in flowering plants, the petals and sepals, the perianth
2.  in bryophytes, the leaves surrounding the antheridia, the perianth, also called a splash cup
perigynous
borne around the ovary, i.e. of perianth segments and stamens arising from a cup-like or tubular extension of receptacle (free from the ovary but extending above its base); cf. epigynous, hypogynous.
persistent
remaining attached to the plant beyond the usual time of falling, for instance sepals not falling after flowering, flower parts remaining through maturity of fruit; compare deciduous, caducous.
perule (lat. perula, perulae)

(adjective: perulate)

1.  the scaly covering of a leaf or flower bud, or reduced scale like leaf surrounding the bud. Buds lacking perulae are referred to as 'naked'
2.  in camellias the final bracts and sepals become indistinguishable and are called perules.
3.  a kind of sac formed by the adherent bases of the two lateral sepals in certain orchids.
petal
in a flower, one of the segments or divisions of the inner whorl of non-fertile parts surrounding the fertile organs, usually soft and conspicuously coloured; compare sepal.
petaloid
like a petal; soft in texture and coloured conspicuously.
petiolate
subtended by a petiole.
petiole
the stalk of a leaf.
petiolule
the stalk of a leaflet.
petricolous
Rock-dwelling; living on or among rocks.
phanerogam
gymnosperms and angiosperms; plants producing stamens and gynoecia; literally plants with conspicuous sexual reproductive organs; cf. cryptogams.
photosynthesis
the process by which sugars are made from carbon dioxide and water in cells containing chloroplasts; the chemical energy required from solar energy in the presence of the pigment chlorophyll.
phyllode
(adjective phyllodineous) a leaf with the blade much reduced or absent, and in which the petiole and or rachis perform the functions of the whole leaf; e.g. many acacias; cf. cladode.
phyllopodium
the part of the stipe that is proximal or basal of the articulation (joint) and remains attached to the rhizome after the frond has detached from the articulation; especially prominent in Elaphoglossum and Oleandra.
phytomelan
also phytomelanous. A black, inert, carbonaceous material that lacks nitrogen, probably derived from catechol, that forms a crust-like covering of some seeds, commonly found in Asparagales, Asteraceae, etc.
pilose
covered with soft, weak, thin and clearly separated hairs, which are usually defined as long and sometimes ascending.
pinna
(plural pinnae) a primary segment of a compound leaf.
pinnate
a compound leaf with leaflets arranged on each side of a common petiole or axis; also applied to how the lateral veins are arranged in relation to the main vein.
pinnatifid
pinnately lobed.
pinnatisect
pinnately divided almost to midrib but segments still confluent.
pinnule
ultimate free division (or leaflet) of a compound leaf, or a pinnate subdivision of a multipinnate leaf.
pistil
1.  a single carpel when the carpels are free.
2.  a group of carpels when the carpels are united by the fusion of their walls.
pith
the central region of a stem, inside the vascular cylinder; the spongy parenchymatous central tissue in some stems and roots.
placenta
the tissue within an ovary to which the ovules are attached.
placentation
the arrangement of ovules inside ovary; for example axile, free-central, parietal, marginal, basal, or apical.
Plant Breeders Rights (PBR)
these rights, governed by Plant Breeder's Rights Acts give the plant breeder legal protection over the propagation of a cultivar, and the exclusive rights to produce and to sell it, including the right to license others to produce and sell plants and reproductive material of a registered, deliberately bred variety. Cf. UPOV.
Plant Variety Rights (PVR)
governed by the Plant Variety Rights the registration of new varieties is now governed by Plant Breeders Rights.
Plastochron
the time between successive leaf initiation events.
plicate
pleated; folded back and forth longitudinally like a fan, such as the leaves of many palm species. (The concept often appears in specific names in forms such as Aloe plicatilis and Acacia plicata. Commonly such names are not correctly appropriate, but are applied to distichous structures rather than plicate.
-plinerved
(of leaves) a suffix indicating that the main nerves are lateral and arise from a point distinctly above the base of the leaf. Combined with a numerical prefix to form words like 3-plinerved, 5-plinerved, and so on. Such leaves are especially characteristic of the family Melastomataceae.
plumose
like a feather; with fine hairs branching from a main axis.
plumule
the part of an embryo that gives rise to the shoot system of a plant; cf. radicle.
pluriflor
having many flowers per inflorescence. See also pauciflor.
pluriovulate
having many ovules as in placentae, carpels or ovaries.
pneumatophore
a vertical, aerial (at low tide) appendage to the roots of some plants, through which gases are exchanged; e.g. on mangroves.
pod
1.  a legume, the fruit of a leguminous plant, a dry fruit of a single carpel, splitting along two sutures.
2.  siliqua and silicula, the fruit of Brassicaceae, a dry fruit composed of two carpels separated by a partition.
pollen
powdery mass shed from anthers (of angiosperms) or microsporangia (of gymnosperms); the microspores of seed plants; pollen-grains.
pollen-mass
pollen-grains cohering by a waxy texture or fine threads into a single body; pollinium; e.g. in orchids.
pollination
the transfer of pollen from the male organ (anther) to the receptive region of a female organ (stigma).
pollinium
see pollen-mass.
polygamodioecious
having bisexual and male flowers on some plants and bisexual and female flowers on others; cf. androdioecious, andromonoecious, dioecious, monoecious, polygamomonoecious, polygamous.
polygamomonoecious
having male, female and bisexual flowers on the same plant; cf. androdioecious, andromonoecious, polygamodioecious, polygamous.
polygamous
having bisexual and unisexual flowers on the same plant.
polymorphic
of several different kinds (in respect to shape and/or size), hence polymorphism. See also monomorphic (a sigle type) and dimorphic (two types)
polyploid
with more than two of the basic sets of chromosomes in the nucleus; any individual (or a cell) containing three or more complete sets of chromosomes. Various combinations of words or numbers with '-ploid' indicate the number of haploid sets of chromosomes; e.g. triploid = 3 sets, tetraploid = 4 sets, pentaploid = 5 sets, hexaploid = 6 sets, and so on.
pome
a fruit that has developed partly from the ovary wall but mostly from the floral tube, e.g., apple.
population
1.  all individuals of one or more species within a prescribed area.
2.  a group of organisms of one species, occupying a defined area and usually isolated to some degree from other similar groups.
3.  in statistics, the whole group of items or individuals under investigation.
posterior
the side nearest the axis; compare anterior.
prickle
(adjective: prickly) hard, pointed outgrowth from the surface of a plant (involving several layers of cells but not containing a vein); sharp outgrowth from the bark, detachable without tearing wood; cf. thorn.
prophyll
a leaf formed at the base of a shoot, usually smaller than those formed later.
pro parte
(Latin) in part; in nomenclature, to denote that the preceding taxon includes more than one currently recognized entity, and that only one of those entities is being considered.
procumbent
spreading along the ground but not rooting at the nodes: not as close to ground as prostrate.
propagules
a structure capable of producing a new plant; includes seeds, spores, bulbils, etc.
prostrate
lying flat on the ground.
protandrous
male sex organs maturing before the female ones, e.g. a flower shedding pollen before the stigma is receptive; cf. protogynous.
prothallus
a gametophyte body, usually flattened and delicate; e.g. in ferns and fern allies.
protogynous
female sex organs maturing before the male ones, e.g. a flower shedding pollen after the stigma has ceased to be receptive; cf. protandrous.
proximal
near the point of origin or attachment; cf. distal.
pruinose
covered with a powdery, waxy material; with a bloom.
pseudanthium
a particular form of inflorescence occurring in many species of the Asteraceae, in which multiple flowers are grouped together to form a flower-like structure, commonly called a head or capitulum.
pseudo
false; apparently but not genuine; e.g. pseudo-bulb = a thickened, bulb-like internode in orchids, or a corm.
pseudostipule
an enlarged, persistent axillary bud scale that resembles a stipule; common in Bignoniaceae.
pseudoverticillate
having the appearance of being whorled (verticillate), without actually being so. See verticillate.
puberulous (puberulent)
covered with minute soft erect hairs.
pubescent
downy; covered with short, soft, erect hairs.
pulvinus
a swelling at the base of a leaf or leaflet stalk, often glandular or responsive to touch.
punctate
marked with dots.
pungent
having a sharp hard point.
pyramidal
of a plant's form, tetrahedral, pyramid-shaped.
pyrene
the stone of a drupe, consisting of the seed surrounded by the hardened endocarp.
pyriform
pear-shaped.

Q[edit]

quadrate
more or less square.

R[edit]

raceme
(adjective racemose) an indeterminate inflorescence in which the main axis produces a series of flowers on lateral stalks, the oldest at the base and the youngest at the top; cf. spike.
rachilla (rhachilla)
the axis of a grass spikelet, above the glumes.
rachis
(plural rachises; rachides) the axis of an inflorescence or a pinnate leaf; for example ferns; secondary rachis is the axis of a pinna in a bipinnate leaf distal to and including the lowermost pedicel attachment.
radial
with structures radiating from a central point as spokes on a wheel, for example, the lateral spines of a cactus.
radiate
of daisies, of a capitulum, with ray florets surrounding disc florets.
radical
springing from the root; clustered at base of stem.
radicle
the part of an embryo giving rise to the root system of a plant; cf. plumule.
rainforest
a forest dominated by broad-leaved trees with dense crowns that form a continuous layer (canopy) and with one or more of the following growth forms: epiphytes, lianas, treeferns, palms; eucalypts absent or are present only as isolated emergen, e.g. in Victoria, mesic vegetation is dominated by trees other than eucalypts, often with lianas and epiphytes.
ramet
an individual member of a clone.
ray
1.  zygomorphic (ligulate) flowers in a radiate flowerhead, that is, ray-florets/flowers, for example Asteraceae.
2.  each of the branches of an umbel.
receptacle
the axis of a flower, in other words, floral axis; torus; for example in Asteraceae, the floral base or common receptacle is the expanded summit of the peduncle on which the flowers are inserted.
recurved
bent or curved backwards or downwards.
reflexed
bent sharply back or down.
registered name
a cultivar name accepted by the relevant International Cultivar Registration Authority.
registered trade mark
a trade mark formally accepted by a statutory trade-mark authority and distinguished by the international ® sign.
registration
1.  the act of recording a new cultivar name with an International Cultivar Registration Authority.
2.  recording a new cultivar name with a statutory authority like the Plant Breeder’s Rights Office.
3.  recording a trade mark with a trade marks office. Compare registered trade mark.
regular
see actinomorphic.
reniform
kidney-shaped.
reticulate
forming a network (or reticulum), e.g. veins that join one another at more than one point.
retrorse
directed backwards or downwards; cf. antrorse.
retuse
with a blunt (obtuse) and slightly notched apex.
revision
an account of a particular plant group, like an abbreviated or simplified monograph. Sometimes confined to the plants of a particular region. Similar to a monograph in clearly distinguishing the taxa and providing a means for their identification; compare monograph.
revolute
rolled under (downwards or backwards), for example when the edges of leaves are rolled under towards the midrib; compare involute.
rhachis
see rachis.
rhizome
a perennial underground stem usually growing horizontally. See also stolon. Abbreviation: rhiz.
rhombic
like a rhombus: an oblique figure with four equal sides; compare trapeziform, trullate.
rhomboid
a four-sided figure with opposite sides parallel but with adjacent sides an unequal length (like an oblique rectangle); see also rhombic.
rhomboidal
a shape, for instance of a leaf, that is roughly diamond-shaped with length equal to width.
root
a unit of a plant's axial system which is usually underground, does not bear leaves, tends to grow downwards, and is typically derived from the radicle of the embryo.
root hairs
outgrowths of the outermost layer of cells just behind the root tips, functioning as water-absorbing organs.
rootstock

short, erect, swollen structure at junction of a plant's root and shoot systems, for example a corm. Also used to describe:

1. a part of a budded or grafted plant which supplies the roots, also called a rootstock, or plants grown specifically to produce these.

2.  plants or seeds with some specific attribute, for instance virus-free plants.
rosette
when parts are not whorled or opposite but appear so, due to the contractions of internodes, e.g. the petals in a double rose or a basal cluster of leaves (usually close to the ground) in some plants.
rostrate
with a beak.
rotate
circular and flattened; for example a corolla with a very short tube and spreading lobes (for instance some Solanaceae).
The runcinate lobes of a Taraxacum officinale leaf point downwards
rudimentary
poorly developed and not functional; compare vestigial.
rugose
wrinkled.
rugulose
finely wrinkled.
ruminate
(usually applied to endosperm). irregularly grooved or ridged; appearing chewed. (a common type of endosperm in Myristicaceae).
runcinate
sharply pinnatifid or cleft, the segments directed downward.
runners
see stolon.
rupicolous
rupestral, saxicolous, growing on or among rocks. (compare epilithic, lithophytic)
rush
a plant belonging to the family Juncaceae or, more loosely, applied to various monocotyledons.

S[edit]

saccate
pouched.
sagittate
shaped like the head of an arrow; narrow and pointed but gradually enlarged at base into two straight lobes directed downwards; may refer only to the base of a leaf with such lobes; cf. hastate.
samara
a dry, indehiscent fruit with its wall expanded into a wing.
samphire
(in Australia) any plant of the tribe Salicorniae (chenopodiaceae), e.g. Sarcocornia, Halosarcia, Sclerostegia; or a community dominated by one or more of these species.
saprophyte
(adjective saprophytic) an organism deriving its nourishment from decaying organic matter and usually lacking chlorophyll; compare parasite, epiphyte.
scabrid (scabrous)
rough to the touch with short hard emergences or hairs.
scale
1.  a reduced or rudimentary leaf, for example around a dormant bud.
2.  a flattened epidermal outgrowth, such as those commonly found on the leaves and rhizomes of ferns.
scandent
climbing, by whatever means. See also: scandent in Wiktionary.
scape
(adjective scapose) a stem-like flowering stalk of a plant with radical leaves.
scapose
having the floral axis more or less erect with a few leaves or devoid of leaves; consisting of a scape.
scarious
dry and membranous.
schizocarp
a dry fruit formed from more than one carpel but breaking apart into individual carpels (mericarps) when ripe.
scion
the aerial part of a graft combination, induced by various means to unite with a compatible understock/roostock.
sclereid
a cell with a thick, often lignified, cell wall that is shorter than a fiber cell and dies soon after the thickening of its cell wall.
sclerenchyma
a strengthening or support tissue composed of sclereids or of a mixture of sclereids and fibers.
sclerophyll
(adjective sclerophyllous) a plant with hard, stiff leaves; leaves stiffened with thick-walled cells.
scorpioid
of a cymose inflorescence, when it branches alternately on one side and then the other; cf. helicoid.
scrubland
dense vegetation dominated by shrubs.
section (sectio)
the category of supplementary taxa intermediate in rank between subgenus and series. It is a singular noun always written with a capital initial letter, in combination with the generic name.
secund
with all the parts grouped on one side or turned to one side (applied especially to inflorescences).
sedge
a plant belonging to the family Cyperaceae.
seed
a ripened ovule, consisting of a protective coat enclosing an embryo and food reserves; a propagating organ formed in the sexual reproductive cycle of gymnosperms and angiosperms (together, the seed plants).
segment
part or subdivision of an organ, for example a petal is a segment of the corolla. A term sometimes used when the sepals and petals are indistinguishable.
self-pollination
also called selfing, the acceptance by stigmas of pollen from the same flower or from flowers on the same plant, which means they are self-compatible.
sensitive
a descriptive term for stigmas that, in response to touch, close the two lobes of the stigma together, ending the receptivity of the stigma, at least for the time that the lobes are closed together. Mimulus is perhaps the best-known example.
sensu
in the sense of.
sensu lato
of a plant name, in its broadest sense.
sensu stricto
of a plant name, in its narrowest sense.
sepal
in a flower, one of the segments or divisions of the outer whorl of non-fertile parts surrounding the fertile organs, usually green; compare petal.
septicidal
of a fruit, when it dehisces along the partitions between loculi; cf loculicidal.
septum
(plural septa) a partition, for example the membranous wall separating the two valves of the pod of Brassicaceae.
sericeous
silky with dense appressed hairs.
series
the category of supplementary taxa intermediate in rank between section and species. It is a plural adjective; for instance Primula subgenus Primula sect. Primula series Acaules.
serrate
toothed with asymmetrical teeth pointing forward; like the cutting edge of a saw.
serrulate
finely serrate.
sessile
without a stalk, e.g. of a stigma, when the style is absent.
seta
(adjectives setose, setaceous) a bristle or stiff hair (in Bryophytes, the stalk of the sporophyte); a terminal seta is an appendage to the tip of an organ, e.g. the primary rachis of a bipinnate leaf in Acacia.
sheath
a tubular or rolled part of an organ, e.g. the lower part of the leaf in most grasses.
shoot
usually the aerial part of a plant; a stem including its dependent parts, leaves flowers etc.
shrub
a woody perennial plant without a single main trunk, branching freely, and smaller than a tree.
sigmoid
shaped like the letter 'S'.
silicula
a stout siliqua (not more than twice as long as wide).
siliqua
a dry, dehiscent fruit (more than twice as long as wide) formed from a superior ovary of two carpels, with two parietal placentas and divided into two loculi by a 'false' septum.
silky
densely covered with fine soft straight appressed hairs, with a lustrous sheen and satiny to the touch.
silviculture
the science of forestry and the cultivation of woodlands for commercial purposes and wildlife conservation.
simple
undivided, for instance a leaf not divided into leaflets (note, however, that a simple leaf may be entire, toothed or lobed) or an unbranched hair or inflorescence.
sinuate
with deep, wave-like depressions along the margins, but more or less flat; compare undulate.
sinus
a notch or depression between two lobes or teeth in the margin of an organ.
solitary
single, of flowers that grow one plant per year, one in each axil, or widely separated on the plant; not grouped in an inflorescence.
spadix
a spicate inflorescence with a stout, often succulent axis.
spathe
a large bract ensheathing an inflorescence. Traditionally any broad flat blade.
spathulate (spatulate)
spoon-shaped; broad at the tip with a narrowed projection extending to the base.
species
a group, or populations of individuals, sharing common features and/or ancestry, generally the smallest group that can be readily and consistently recognized; often, a group of individuals capable of interbreeding and producing fertile offspring. The basic unit of classification, the category of taxa of the lowest principal rank in the nomenclatural hierarchy.
specific epithet
follows the name of the genus, and is the second word of a botanical binomial. The generic name and specific epithet together constitute the name of a species; i.e. the specific epithet is not the species name.
spica
(adjective spicate) a spike.
spike
(adjective spicate) an unbranched, indeterminate inflorescence in which the flowers are without stalks; cf. raceme.
spikelet
a unit of the inflorescence especially in grasses, sedges and some other monocotyledons, consisting of one to many flowers and associated bracts (glumes).
spine
(adjective spinose) a stiff, sharp structure, formed by the modification of a plant organ that contains vascular tissue; e.g. a lateral branch or a stipule; includes thorns.
spinescent
ending in a spine; modified to form a spine.
spiral
of arrangement, when plant parts are arranged in a succession of curves like the thread of a screw, or coiled in a cylindrical or conical manner.
sporangium (sporangia)
a structure in which spores are formed.
sporangiophore
an organ bearing sporangia, e.g. in the cones of Equisetum.
spore
in non-flowering plants only a simple propagule, produced either sexually or asexually, and consisting of one or a few cells.
sporocarp
a fruiting body containing spores.
sporophyll
a modified leaf that bears a sporangium or sporangia, in pteridophytes.
sporophyte
a plant, or phase of a life cycle, that bears the spores; cf. gametophyte.
sport
a naturally occurring variant of a species, not usually present in a population or group of plants; a plant that has spontaneously mutated so that it differs from its parent plant.
spreading
extending horizontally, for example branches; standing out at right angles to axis, for example leaves or hairs.
spur
1.  a short shoot.
2.  a conical or tubular outgrowth from the base of a perianth segment, often containing nectar.
s.t.
abbreviation for sometimes, compare usu. and oft.
stalk
the supporting structure of an organ, usually narrower in diameter than the organ.
stamen
(adjective staminate) male organ of a flower, consisting (usually) of a stalk (filament) and a pollen-bearing portion (anther).
staminode
a sterile stamen, often rudimentary, sometimes petal-like.
standard
the large posterior petal of pea-flowers.
standard specimen
a representative specimen of a cultivar (or other taxon), one that demonstrates how the name of that taxon should be used.
stellate
star-shaped, for example a type of hair.
stem
the plant axis, either aerial or subterranean, which bears nodes, leaves, branches and flowers.
stem-clasping
see amplexicaul.
stenospermocarpy
the development or production of fruit that is seedless or has minute seeds because of the abortion of seed development. compare parthenocarpy
sterile
infertile, for example a stamen that does not bear pollen, or a flower that does not bear seed.
stigma
the pollen-receptive surface of a carpel or group of fused carpels, usually sticky; usually a point or small head at the summit of the style.
stipe
in ferns, the stalk of a frond; generally a small stalk.
stipella
(stipel; plural stipellae) one of two small secondary stipules at the base of leaflets in some species.
stipitate
stalked; borne on a stipe; of an ovary, borne on a gynophore.
stipulate
bearing stipules.
stipule
small appendage at the bases of leaves in many dicotyledons.
stolon
slender, prostrate or trailing stem, producing roots and sometimes erect shoots at its nodes. See also rhizome.
stoloniferous
having stolons.
stoma
(plural stomata) a pore; small hole in the surface of a leaf (or other aerial organ) allowing the exchange of gases between tissues and the atmosphere.
striate
striped with parallel, longitudinal lines or ridges.
strigose
covered with appressed, rigid, bristle-like, straight hairs; the appressed equivalent of hispid.
strobilus
(plural strobili) a cone-like structure consisting of sporophylls (e.g. conifers and club mosses) or sporangiophores (e.g. in Equisetopsida) borne close together on an axis.
style
an elongated part of a carpel, or group of fused carpels, between the ovary and the stigma.
stylodium
an elongate stigma that resembles a style, a false style, e.g. commonly found in Poaceae and Asteraceae.
stylulus
the elongated apex of a free carpel which functions like the style of a syncarpous ovary, allowing pollen tubes from its stigma to enter the locule of only that carpel.
subgenus
the category of supplementary taxa intermediate between genus and section. It is a singular noun, always has a capital initial letter and is used in combination with the generic name; e.g. Primula subgenus Primula.
subglobose
Inflated, but less than spherical. See also globose.
subshrub
undershrub; small shrub which may have partially herbaceous stems, but generally a woody plant less than 1 m high.
subspecies
a grouping within a species, usually used for geographically isolated and morphologically distinct entities. Its taxonomic rank occurs between species and variety.
subtend
to stand beneath or close to, as in a bract at the base of a flower.
subquadrangular
not quite square; see also quadrangular in wiktionary.
subulate
narrow and tapering gradually to a fine point.
succulent
juicy, fleshy; a plant with a fleshy habit.
sucker
a shoot of more or less subterranean origin; an erect shoot originating from a bud on a root or a rhizome, sometimes at some distance from the stem of the plant.
suffrutex
subshrub or undershrub.(plural suffrutices). See also suffrutex for etymology etc.
sulcate
furrowed; grooved.
superficial
on the surface.
superior
of an ovary, borne above the level of attachment of the other floral parts, or above the base of a floral tube (that is, one that is free from the ovary and bears the perianth and stamens); compare inferior, half-inferior.
suspended
of an ovule, when attached slightly below the summit of the ovary; compare pendulous.
suture
a junction or seam of union. (see fissure, commissure)
sward
extensive, more or less even cover of a surface, for example a lawn grass; compare tussock.
sympatric
with more or less similar or overlapping ranges of distribution.
syconium
a hollow infructescence containing multiple fruit, such as that of a fig.
syn- (sym-)
with, together.
sympetalous
with united (connate or fused) petals.
synangium
a fused aggregate of sporangia.
synaptospermy
The dispersal of diaspores as units, where each bears more than one seed, for example where each diaspore comprises an entire inflorescence, as in Brunsvigia or multi-seeded fruit as in Tribulus zeyheri. Ephemeral synaptospermy is the term for when the diaspores split into units containing fewer or single seeds each, as in most tumbleweeds. True synaptospermy is when the diaspore generally remains entire until germination, as commonly happens in species of Grielum.
syncarpous
of a gynoecium, made up of united carpels.
synonym
outdated name or 'alternative' name for the same taxon.

T[edit]

taproot
the main, descending root of a plant with a single dominant root axis.
taxon
(plural taxa) a group or category in a system of classification, derived from the Greek prefixes taxo-, taxis- meaning arrangement.
taxonomy
the study of the principles and practice of classification.
tegmen
the inner layer of the testa (seed coat). It develops from the inner integument of the ovule.
tendril
a slender organ (modified e.g. from stem, leaf, leaflet or stipule) used by climbing plants to cling to an object.
tepal
perianth segment, either sepal or petal; usually used when all perianth segments are similar in appearance; cf. petal.
terete
circular in cross-section; more or less cylindrical.
terminal
situated at the tip or apex.
ternate
in groups of three; of leaves, arranged in whorls of three; of a single leaf, with the leaflets arranged in groups of three. See Leaf shape.
terrestrial
generally denotes of or on the ground; of habitat, on land as opposed to in water (aquatic) or on rocks (lithophytic), or other plants (epiphytic), and so on.
testa
seed coat.
tetrad
a group of four; usually means four pollen grains remaining fused together a maturity, e.g. in the Epacridaceae.[4]
tetramerous
in four parts, particularly with respect to flowers, four parts in each whorl. See also trimerous and pentamerous.
tetraspore
the asexual spore of red algae. It is so named because each sporangium produces just four spores. See Rhodophyceae.[5]
thorn
a sharp, stiff point, usually a modified stem, that cannot be detached without tearing the subtending tissue; a spine; cf. prickle.
throat
the opening of a corolla or perianth.
thyrse
a branched inflorescence in which the main axis is indeterminate (racemose) and the lateral branches determinate (cymose).
tomentum
(adjective tomentose) a dense covering of short, matted hairs. Tomentose is often used as a general term for bearing an indumentum, but this is not a recommended use.
toothed
with a more or less regularly incised margin.
torus
see receptacle.
trademark (trade mark)
a distinctive word, picture, symbol, smell or other device or any combination or multiples of these. It must not be descriptive of the goods or services, nor can it be geographical nor a surname. Used to distinguish one trader from another, compared with PBR which protect the commercial name of a particular plant variety.
trapeziform
1.  like a trapezium (a four-sided figure with two parallel sides of unequal length)
2.  like a trapezoid (a four-sided figure, or quadrilateral, with neither pair of sides equal); sometimes used erroneously as a synonym for rhombic.
tree
a woody plant, usually with a single distinct trunk and generally more than 5 m tall.
triad
a group of three.
triangular
planar and with 3 sides.
tribe
a taxonomic grouping, in rank between genus and species.
trichome
in non-filamentous plants, any hair-like outgrowth from epidermis, e.g. a hair or bristle; sometimes restricted to unbranched epidermal outgrowths.
trifid
split into three parts. See also bifid.
trifoliolate (or trifoliate)
a compound leaf of three leaflets, for example a clover leaf.
trigonous
triangular in cross-section and obtusely angled; cf. triquetus.
trimerous
in three parts, particularly with respect to flowers, three parts in each whorl. See also tetramerous and pentamerous.
trinerved
having three nerves or veins.
triplinerved
(of leaves) having three main nerves with the lateral nerves arising from the midnerve above the base of the leaf.
triquetrous
more or less triangular in cross-section, but acutely angled (with 3 distinct longitudinal ridges); cf. trigonus.
trivalve
also trivalvar. Divided into three valves. See also bivalve
trivial name
the second word in the two-part scientific name of an organism; cf. specific epithet.
trophophyll
a vegetative, nutrient-producing leaf or microphyll, whose primary function is photosynthesis. It is not specialized or modified for some other function. (compare: sporophyll).
trullate
ovate but angled; like a bricklayer's trowel; inverse kite-shaped; compare rhombic.
truncate
cut off squarely; with an abruptly transverse end.
trunk
the upright large main stem of a tree.
truss
a compact cluster of flowers or fruits arising from one centre; for instance, evident in many rhododendrons.
tuber
an underground storage organ formed by the swelling of an underground stem which produces buds and stores food, forming a seasonal perennating organ, for example potato; compare tuberoid.
tubercle
a small wart-like outgrowth.
tuberculate
covered in tubercles; warty.
tuberoid
an underground storage organ formed by the swelling of a root; occurs in many orchids.
tuberous
resembling a tuber; producing tubers.
tubular
with the form of a tube or cylinder.
tunic
outer covering of some bulbs and corms.
turbinate
top-shaped.
turgid
swollen with liquid; firm; compare flaccid.
tussock
a dense tuft of vegetation, usually well separated from neighbouring tussocks, for example some grasses; compare sward.
two-ranked
having leaves arranged in two rows in the same plane, on opposite sides of the branch; = distichous.
type
an item (usually a herbarium specimen) to which the name of a taxon is permanently attached, i.e. a designated representative of a plant name. Important in determining the priority of names available for a particular taxon.
type genus
in nomenclature, the genus from which the family is based.
typography
the presentation of printed matter, covering issues such as type styles (e.g. italic or roman type), underlining, emboldening and letter spacing.

U[edit]

umbel
(adjective umbellate) a racemose inflorescence in which all the individual flower stalks arise in a cluster at the top of the peduncle and are of about equal length; in a simple umbel, each stalk is unbranched and bears only one flower; a cymose umbel is an apparent umbel but its flowers open centrifugally.
umbonate
with a conical or blunt projection arising from a flatter surface, as on the top of a mushroom, or in the scale of a pine cone.
uncinate
with a hook at the apex.
undershrub
a low shrub, often with flowering branches that die off in winter; cf. subshrub.
undulate
wavy and not flat; compare sinuate.
unilocular
having one loculus or chamber, e.g., the ovary in the families Proteaceae and Fabaceae.
uniserial
Arranged in a single row or series. Unbranched. Uniseriate.
uniseriate
Arranged in a single row or series. Unbranched. Uniserial.
unisexual
of one sex; bearing only male or only female reproductive organs.
unitegmic
(of an ovule), covered by a single integument.
urceolate
urn-shaped.
usu.
abbreviation for usually, compare s.t. and oft.
utricle
a small bladder; a membranous bladder-like sac enclosing an ovary or fruit; in sedges a fruit in which the pericarp is larger than, and loosely encloses, the seed.

V[edit]

vallecular canal
a resin canal coinciding with a longitudinal groove in the seeds of Asteraceae. A longitudinal cavity in the cortex of the stems of Equisetum, coinciding with a groove in the stem surface.
valvate
of sepals and petals in bud, which meet edge to edge but do not overlap.
valve
a portion of an organ that fragments or splits open, for example the teeth-like portions of a pericarp in a split (dehisced) capsule or pod when ripe.
var
see varietas.
variant
a plant or group of plants showing some measure of difference from the characteristics associated with a particular taxon.
varietas (variety in common usage, abbreviated as var.)
(Latin) in the Linnean hierarchy a rank below that of species, between the ranks of subspecies and form.
variegated
irregularly marked with blotches or patches of another colour.
Vasculum
Container used by botanists for collecting field specimines.
vein
a strand of vascular tissue; nerve.
veinlet
a small vein; the ultimate (visible) division of a vein.
velvety
densely covered with fine, short, soft, erect hairs.
venation
the arrangement of veins in a leaf.
ventral
the front; in particular, towards the axis in a lateral organ or towards substratum in prostrate plant; compare dorsal.
vernation
the arrangement of unexpanded leaves in a bud; the order of unfolding of leaves from a bud.
verrucose
with warts.
versatile
of anthers, swinging freely about the point of attachment to the filament.
verticillate
arranged in one or more whorls, i.e. several similar parts arranged at the same point of the axis. e.g. leaf arrangement. Hence pseudoverticillate, appearing whorled or verticillate but not so
vescicular
of hairs, bladder-like; vesciculous, bearing such hairs.
vessel
a capillary tube formed from a series of open-ended cells in the water-conducting tissue of a plant.
vestigial
reduced in form and function from the normal or ancestral condition.
villous
Abounding in or covered with long, soft, straight hairs; shaggy with soft hairs.
vine
1.  Vitis.
2.  Scandent plants climbing by means of trailing or twining stem or runner.
3.  Such a stem or runner[2][6]
virgate Terminology for a class of habit
Wand-shaped, twiggy, especially referring to erect, straight stems. Diminutive: virgulate. In mycology, referring to a pileus with radiating ribs or lines.
viscid
sticky; coated with a thick, syrupy secretion.
viviparous
1.  seeds or fruits which germinate before being shed from the parent plant.
2.  the development of plantlets on non-floral organs e.g. leaves.

W[edit]

Watershoots
warty
a surface covered with small round protuberances, especially in fruit, leaves, twigs and bark, see tuberculate.
watershoot
an erect strong-growing or epicormic shoot developing from near the base of a shrub or tree, but distinct from a sucker.
weed

loosely defined as a plant growing where it is not wanted; commonly associated with disrupted habitats

1. agricultural weed: a plant which taints produce or pollutes crops.

2.  environmental weed: naturalised, exotic or ecologically 'out-of-balance' indigenous species outside the agricultural or garden context which, as a result of invasion, adversely affects the survival or regeneration of indigenous species in natural or partly natural vegetation communities (Carr, G.W., in Foreman & Walsh, 1993).
wild
originating from a known wild habitat (wilderness). See Wildlife.
whorl
a ring of organs borne at the same level on an axis, for example leaves, bracts or floral parts.
wing
1.  a membranous expansion of a fruit or seed which aids in dispersal, for instance on pine seeds.
2.  a thin flange of tissue extending beyond the normal outline of a structure, e.g. on the column of some orchids, on stems, on petioles.
3.  one of the two lateral petals of a flower of subfamily Faboideae of family Fabaceae, located between the adaxial standard (banner) petal and the two abaxial keel petals.
woolly
very densely covered with long, more or less matted or intertwined hairs, resembling sheep's wool.

X[edit]

xeromorph
a plant with structural features (e.g. hard or succulent leaves) or functional adaptations that prevent water loss by evaporation; usually associated with arid habitats, but not necessarily drought-tolerant; cf. xerophyte.
xerophyte
a plant generally living in a dry habitat, typically showing xeromorphic or succulent adaptation; a plant able to tolerate long periods of drought; cf. xeromorph.

Z[edit]

zygomorphic
bilaterally symmetrical; symmetrical about one vertical plane only; applies to flowers in which the perianth segments within each whorl vary in size and shape; compare actinomorphic, irregular.
zygote
a fertilized cell.

See also[edit]

References[edit]

  1. ^ Shreve, Forrest; Wiggins, Ira. Vegetation and Flora of the Sonoran Desert. Stanford University Press, 1964. ISBN 978-0804701631
  2. ^ a b Jackson, Benjamin, Daydon; A Glossary of Botanic Terms with their Derivation and Accent; Published by Gerald Duckworth & Co. London, 4th ed 1928
  3. ^ Alan W. Meerow, Michael F. Fay, Charles L Guy, Qin-Bao Li, Faridah Q Zaman, Mark W. Chase. Systematics of Amaryllidaceae based on cladistic analysis of plastid sequence data. Am. J. Bot. September 1999 vol. 86 no. 9 1325-1345
  4. ^ Wikisource-logo.svg Beach, Chandler B., ed. (1914). "Tetrad". The New Student's Reference Work. Chicago: F. E. Compton and Co. 
  5. ^ Wikisource-logo.svg Beach, Chandler B., ed. (1914). "Tetraspore". The New Student's Reference Work. Chicago: F. E. Compton and Co. 
  6. ^ Brown, Lesley (1993). The New shorter Oxford English dictionary on historical principles. Oxford [Eng.]: Clarendon. ISBN 0-19-861271-0. 

Bibliography[edit]

  • Stearn, W.T. 1983. Botanical Latin. David & Charles, North Pomfret, Vermont.
  • Benjamin D. Jackson. A Glossary of Botanic Terms. Duckworth: London. J.B. Lippincott Company: Philadelphia (1928).
  • Michael Hickey and Clive King. 2001. The Cambridge Illustrated Glossary of Botanical Terms. Cambridge University Press: U.K.. ISBN 978-0-521-79401-5
  • James G. Harris and Melinda Woolf Harris. Plant Identification Terminology: An Illustrated Glossary. Spring Lake Publishing: Spring Lake, UT, USA. (1994).
  • David B. Lellinger. 2002. A Modern Multilingual Glossary for Taxonomic Pteridology (Pteridologia, 3). American Fern Society. ISBN 978-0-933500-02-0.
  • Ernest M. Gifford and Adriance S. Foster. 1989. Morphology and Evolution of Vascular Plants, 3rd edition. W. H. Freeman. ISBN 978-0-7167-1946-5

External links[edit]

Royal Botanical Gardens at Kew[edit]