Maloideae
From Wikipedia, the free encyclopedia
| Maloideae | |
|---|---|
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| Malus sikkimensis fruit | |
| Scientific classification | |
| Kingdom: | Plantae |
| Division: | Magnoliophyta |
| Class: | Magnoliopsida |
| Order: | Rosales |
| Family: | Rosaceae |
| Subfamily: | Maloideae[1] or Spiraeoideae [2] |
| Genera | |
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See text |
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The Maloideae are the apple subfamily, a grouping traditionally used by some taxonomists within the rose family, Rosaceae. Approximately 28 genera have been included by various authors, including approximately 1100 species worldwide, with most species occurring in the temperate Northern Hemisphere. The group includes a number of plants bearing commercially important fruits, such as apples and pears, while others are cultivated as ornamentals.
In its traditional circumscription[1] this subfamily consisted exclusively of shrubs and small trees characterised by a pome, a type of accessory fruit that does not occur in non-Maloid Rosaceae, and by a basal haploid chromosome count of 17 (instead of 7, 8, or 9 as in the other subfamilies). The syncarpous flowers have one to five carpels which are at least partly fused to each other and to the hypanthium (floral cup), making the ovary at least three-quarters inferior, though it is said[citation needed] that the flowers in the genera Cotoneaster, Heteromeles, and Pyracantha are completely apocarpous, i.e. with carpels free from each other. The hypanthium with the ovaries matures into the pome fruit. The leaves of the plants in this group are evergreen or deciduous. These leaves come in a wide variety of shapes from simple leaves with entire, toothed or pinnately lobed margins to pinnately compound leaves. They can be thin (membranaceous) or with a leathery texture (coriaceous)[3].
[edit] Taxonomy
The subfamily was earlier known as Pomoideae, a name that is no longer accepted under the International Code of Botanical Nomenclature. It has also been separated into its own family the Malaceae[4] or Pomaceae[5].
Recent molecular data have shown that subfamily Maloideae evolved from within subfamily Spiraeoideae[6], as did the traditional subfamily Prunoideae[2], and to best reflect relationships subfamily Spiraeoideae has been expanded. With this classification the traditional Maloideae are considered to be part of Spiraeoideae[2]. An earlier intermediate classification[7] expanded Maloideae to include four genera with dry non-pome fruit. These are Kageneckia, Lindleya, and Vauquelinia, which have a haploid chromosome count of 15 or 17, and Gillenia, which is herbaceous and has a haploid chromosome count of 9.
A traditional circumscription of Maloideae includes two tribes, Maleae and Crataegeae[1]. In a more recent classification[2] this is equivalent to subtribe Pyrinae, which includes the following genera:
Amelanchier - serviceberry, juneberry
Aria (see Sorbus)
Aronia - chokeberry
Chaenomeles - Japanese quince
Chamaemeles
Chamaemespilus (see Sorbus chamaemespilus)
Cormus (see Sorbus)
Cotoneaster - cotoneaster
Crataegus - hawthorn
Cydonia - quince
Dichotomanthes
Docynia
Docyniopsis
Eriobotrya - loquat
Eriolobus
Hesperomeles
Heteromeles - toyon
Malacomeles
Malus - apple, crabapple
Mespilus - medlar
Osteomeles
Peraphyllum
Photinia
Pseudocydonia - Chinese quince
Pyracantha - firethorn
Pyrus - pear
Rhaphiolepis - hawthorn
Sorbus - rowan, whitebeam, service tree
Stranvaesia = Photinia pro parte
Torminalis (see Sorbus torminalis)
intergeneric hybrids[8]:
×Amelasorbus
×Crataegosorbus
×Crataemespilus
×Malosorbus
×Sorbocotoneaster
×Sorbopyrus
and graft hybrids:
+Crataegomespilus
+Pyrocydonia (Pirocydonia)
The additional genera included in tribe Pyreae are:
Kageneckia
Lindleya
Vauquelinia
And supertribe Pyrodae also includes:
Gillenia
[edit] Notes
- ^ a b c G. K. Schulze-Menz 1964. Reihe Rosales. in A. Engler's Syllabus der Pflanzenfamilien mit besonderer Berücksichtigung der Nutzpflanzen nebst einer Übersicht über die Florenreiche und Florengebiete der Erde, Gebrüder Borntraeger, Berlin
- ^ a b c d Potter, D.; Eriksson, T.; Evans, R.C.; Oh, S.H.; Smedmark, J.E.E.; Morgan, D.R.; Kerr, M.; Robertson, K.R.; Arsenault, M.P.; Dickinson, T.A.; Campbell, C.S. (2007). Phylogeny and classification of Rosaceae. Plant Systematics and Evolution. 266(1–2): 5–43.
- ^ Kenneth R. Robinson, James B. Phipps, Joseph R. Rohrer (1992). "Summary of the leaves in the genera of Maloideae (Rosaceae)". Annals if the Missouri Botanical Garden 79 (1): 81–94. doi:.
- ^ GRIN Taxonomy for Plants
- ^ Lindley, J. (1822). Observations on the natural group of plants called Pomaceae. Transactions of the Linnean Society of London. 13: 88–106.
- ^ Morgan, D.R.; Soltis, D.E.; Robertson, K.R. (1994). Systematic and evolutionary implications of rbcL sequence variation in Rosaceae. American Journal of Botany. 81(7): 890–903.
- ^ Evans, R. C., Campbell, C. S. (2002). "The origin of the apple subfamily (Maloideae; Rosaceae) is clarified by DNA sequence data from duplicated GBSSI genes". American Journal of Botany 89(9): 1478–1484. doi:.
- ^ Stace, C.A. 1975. Hybridization and the flora of the British Isles. Academic Press, London.
[edit] References
- Joseph R. Rohrer, Kenneth R. Robinson, James B. Phipps - Floral Morphology of Maloideae (Rosaceae) and its systematic Relevance; American Journal of Botany, 81 (5), P. 574-581; 1994
