Dracophyllum fiordense
Fiordland grass tree | |
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Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Asterids |
Order: | Ericales |
Family: | Ericaceae |
Genus: | Dracophyllum |
Species: | D. fiordense
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Binomial name | |
Dracophyllum fiordense W.R.B.Oliv. 1928
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Dracophyllum fiordense, commonly known as Fiordland grass tree, is a species of tree or shrub endemic to the South Island of New Zealand. In the heath family Ericaceae, it reaches a height of 1.5–5.0 m (5–16 ft), and has leaves which form tufts at the end of its branches. It has long, thin, green leaves with a distinctive curled spiral at their tips, and a pyramid-shaped inflorescence that is hidden under the clump of leaves. It has tiny pink flowers, between 113 and 120 on each panicle, and equally tiny reddish-brown dry fruit. D. fiordense inhabits forests, both lowland and subalpine, shrubland, and even tussock grassland, on mountain slopes, gullies and ridges. Its range occurs in two main groups, one in Fiordland National Park, and one in the Mount Cook and Westland National Parks.
D. fiordense was first described by the New Zealand naturalist Walter Oliver in 1928 and placed by him in the subgenus Dracophyllum. A cladistic analysis using genetic sequencing was published in 2010, revealing that D. fiordense was indeed related to D. menziesii as Oliver had thought. Its conservation status was assessed in 2017 as "Declining."
Description
Dracophyllum fiordense is a tree or tall shrub that grows to heights of 1.5–5.0 m (5–16 ft). It is rarely branched but when it is, they grow upright and have greyish-brown bark on older sections, whilst newer growth is a yellow-brown. The bark is often very flaky and fragmented near the base of old stems. The leaves of D. fiordense are concentrated at the end of their branches, similar to species in the family Bromeliaceae, and are sheathed in 60–87 by 30–43 mm (2.4–3.4 by 1.2–1.7 in) leathery, grooved sheaths, that have a smooth edge which gradually coming to a point. The leaves are leathery too, hairless and deeply grooved, with a straight-triangular- to lance-shaped form. They are 40–70 by 4–5 cm (15.7–27.6 by 1.6–2.0 in) and have very finely toothed edges, with 10–15 teeth every 1 cm (0.4 in). The tip of the leaf is pointed and curls round in a distinctive spiral.[2][3]
Flowering occurs from January to March, producing an inflorescence (flower spike) that is an axillary panicle, which is one that is many-branched and arises far below the leaves, between the stem the leaf. It is also pyramid shaped and much shorter than the leaves, drooping downwards to a length between 10 and 15 cm (4 and 6 in). Both the rachis (inflorescence stem) and the pedicel (individual flower stem) are hairless. The basal branch of the inflorescence extends horizontally outwards and is between 2 and 5 cm (0.8 and 2.0 in) long, whilst the light green inflorescence bracts are 4.0–5.1 by 1.8–2.1 cm (1.6–2.0 by 0.7–0.8 in). In addition, the bracts are hairless except for a margin covered with many small hairs (ciliate), grow over top of the flowers, and fall off early (caducous). They also are egg to triangle shaped at their bases.
There are between 113 and 120 flowers on each panicle, which group in sets on ten near the base. They hang off of hairless 0.8–1.5 mm (0.03–0.06 in) pedicels, which have caducous 4.5–5.0 by 0.8–1.0 mm (0.18–0.20 by 0.03–0.04 in) hairless bracteoles (smaller bracts) in the middle. Its sepals are egg-shaped, 2.0–2.5 by 2.0–3.0 mm (0.08–0.10 by 0.08–0.12 in), which is shorter than the corolla tube, are grooved, and are hairless, except for an edge that is ciliate. The corolla (all of the petals together) is a pink colour and its tube is 2.0–2.5 by 2.0–2.5 mm (0.08–0.10 by 0.08–0.10 in) and bell-shaped, becoming wider towards the mouth. The corolla also has reflexed and oblong-shaped lobes, that are alone a similar size to the corolla tube at 1.5–2.0 by 1.3–1.5 mm (0.06–0.08 by 0.05–0.06 in), and are hairless, with obtuse apices. The stamens are hypogynous, and are made up of a light yellow oblong 1.5–2.0 mm (0.06–0.08 in) anther (pollen containing part) atop a 2.3–2.5 mm (0.09–0.10 in) filament. It has an almost globe-shaped ovary, which is 0.9–1.0 by 1.3–1.5 mm (0.04–0.04 by 0.05–0.06 in), hairless, and has a round apex. The nectary scales are rectangle shaped, 0.6–0.7 by 0.6–0.7 mm (0.02–0.03 by 0.02–0.03 in), and have a notched (retuse) apex. The style projects outwards and is 1.8–2.0 mm (0.07–0.08 in) long, hairless and five-lobed.[2][3]
Fruiting occurs throughout the year, producing an egg-shaped brown 0.55–0.6 mm (0.02–0.02 in) long seed, which has a testa that is somewhat reticulate, and is encased within a 2.0–2.8 by 2.5–4.0 mm (0.08–0.11 by 0.10–0.16 in) red-brown fruit. The fruit is globe shaped but pressed in on itself and has a round apex. The seeds are small enough to be dispersed by the wind.[2] Dracophyllum fiordense is similar to D. menziesii and D. townsonii in that its inflorescences develop below the cluster of leaves, though its one is more branched than that of D. menziesii. D. traversii is also similar, but D. fiordense has a mostly unbranched stem, spiralled ends to its leaves, and an inflorescence occurring below the leaves.[3]
Taxonomy
Dracophyllum fiordense was first described by the New Zealand naturalist and ornithologist Walter Oliver (1883–1957) in the 1928 issue of the Transactions and Proceedings of the New Zealand Institute, though only published in 1929.[note 1] He noted, in what was the first major monograph of the genus,[4] that its leaves were "the largest of all the species of Dracophyllum," and concentrated themselves in "an immense cluster at the top of the stem." Oliver claimed it had been known by others for some years before he collected it in March 1927 on Wilmot saddle and Mount Barber.[5] The type specimen was collected on Wilmot saddle on the Wilmot pass,[note 2] which Oliver designated in a 1952 supplement to his original article.[3][6]
Etymology
Dracophyllum is from the genus's similarity to the species in the genus Dracaena from the Canary Islands and is from the Ancient Greek for "dragon-leaf."[7] The specific epithet fiordense is after the Fiordland region, which makes up one of its two main distributions.[3] It is commonly called the Fiordland grass tree.[8]
Phylogeny
In 1928 Oliver published his first attempt to establish subgenera for Dracophyllum and placed D. fiordense in the subgenus Dracophyllum (then called Eudracophyllum) in the group of D. menziesii, together with D. menziesii and D. townsonii. He citied the way its panicles formed below its terminal cluster of leaves as enough to move it into that group; this placement is unchanged in his 1952 supplement.[5][6] In 2010 several botanists, including Stephanus Venter, published an article on the genus Dracophyllum in the Annals of the Missouri Botanical Garden. In it they performed a cladistic analysis and produced a phylogenetic tree of the tribe Richeeae and other species using genetic sequencing. They found that only the subgenus Oreothamnus and the tribe Richeeae were monophyletic. The paraphylly of the genus Dracophyllum, as well as the polyphyly of the closely related genus Richea, they argued, suggested that a major taxonomic revision was required.[9] Venter revised the genus in 2021, merging the genus Richea into two subgenera, named D. Subg. Cystanthe and D. Subg. Dracophylloides, of Dracophyllum. Though he noted that because the 2010 study was based on plastid sequence data and did not attain some species with strong enough evidence, the subgenera are instead based on morphological characteristics. D. fiordense is kept in the subgenus Dracophyllum under his assessment.[10]
Dracophyllum fiordense is placed in a clade with D. menziesii, nested within a larger clade which includes D. traversii, D. townsonii and D. latifolium. Its placement can be summarised in the following cladogram:
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Distribution and habitat
Dracophyllum fiordense is endemic to the Fiordland and western Otago regions on the South Island of New Zealand and occurs in two main populations. The first is in the Mount Cook and Westland National Parks and the second is in Fiordland National Park.[3] Research by David A. Norton published in 2018 in the New Zealand Journal of Botany, however, found that it occurs much further north than previously recorded. Norton found the species occurring 60 to 75 km (37 to 47 mi) further north (a 15% increase) than its previously known range, in the Waitaha and Hokitika River catchments. He hypothesised that this change in range was due either to: misidentification as D. traversii; simply not having being found earlier; or more recent movement of the species further north. Venter recorded in his 2009 thesis and 2021 revision of the genus that plants from the southern population, found in Fiordland, tend to have few or no branches off the main stem, and have longer leaves and larger fruit. Though he hypothesised that this may be due to the higher elevation, as, for example, plants from valleys on Mt. Alexander reach 5 m (16 ft), whereas others in more alpine regions reach just 50 cm (2 ft).[3][11] The northern population, in Westland, typically has many branched stems and much smaller fruit and shorter leaves. Norton, however, claimed he hadn't seen individuals with as many branches as Venter had illustrated in his thesis in the northern population. The branches of southern plants off the main stem, according to Norton, are only rarely present and when they are they occur at the base of the plant.[12]
Dracophyllum fiordense grows on 50˚–80˚ steep mountain slopes from 50 to 1,280 m (160 to 4,200 ft). It typically occurs on north, north-west, or north-eastern facing slopes in gullies, ravines, ridges, or bluffs. Vegetation in these areas is commonly made up of moist lowland and subalpine forest, shrubland, or tussock grassland. Tree cover comes from either Silver Beech (Nothofagus menziesii), tūpare (Olearia colensoi), mountain flax (Phormium cookianum), or tussock grasses (from the genus Chionochloa).[11] Soil content is principally a brown clay loam formed from schist and gneiss, and is often rich in humus. D. fiordense usually prefers sunny areas, though sometimes can be found in places with light shade. These regions have high rainfall, though it can also gain moisture from mist.[3] A 2017 assessment using the New Zealand Threat Classification System classified it as "Declining," with an estimated habitat area less than 100 km2 (10,000 ha).[1]
References
Notes
- ^ This journal is now called the "Transactions and Proceedings of the Royal Society of New Zealand."
- ^ The code for the lectotype in the Te Papa Tongarewa herbarium is "WELT55115."[3]
Citations
- ^ a b NZTCS 2017
- ^ a b c de Lange 2012.
- ^ a b c d e f g h i Venter 2021, pp. 18–22.
- ^ Venter 2021, p. 3.
- ^ a b Oliver 1928, pp. 705–706.
- ^ a b Oliver 1952, p. 14.
- ^ Eagle 2006, p. 564.
- ^ Mirza 2005, p. 187.
- ^ Wagstaff et al. 2010, pp. 235–258
- ^ Venter 2021, p. 205.
- ^ a b Venter 2009, pp. 163–171.
- ^ Norton 2018, pp. 430–437.
Bibliography
Journals
- Oliver, Walter R. B. (1928). "A Revision of the Genus Dracophyllum". Transactions and Proceedings of the New Zealand Institute. 59 – via Papers Past.
- Oliver, Walter R. B. (1952). "A Revision of the Genus Dracophyllum: Supplement". Transactions and Proceedings of the Royal Society of New Zealand. 80 – via the Internet Archive.
- Wagstaff, Steven J.; Dawson, Murray I.; Venter, Stephanus; Munzinger, Jérôme; Crayn, Darren M.; steane, Dorothy A; Lemson, Kristina L. (2010). "Origin, Diversification, and Classification of the Australasian Genus Dracophyllum (Richeeae, Ericaceae) 1". Annals of the Missouri Botanical Garden. 97 (2). doi:10.3417/2008130. ISSN 0026-6493. JSTOR 40732242. S2CID 3933162.
- Norton, David A. (2018-10-02). "A substantial northward extension of the range of Dracophyllum fiordense W.R.B. Oliv. (Ericaceae), Westland, New Zealand". New Zealand Journal of Botany. 56 (4). doi:10.1080/0028825X.2018.1491863. ISSN 0028-825X.
- Venter, Stephanus (March 2021). "A taxonomic revision of the Australasian genera Dracophyllum and Richea (Richeeae: Styphelioideae: Ericaceae)". Australian Systematic Botany. 34 (2): 18–22. doi:10.1071/SB19049_CO. ISSN 1030-1887.
Websites
- de Lange, Peter (2012). "Dracophyllum fiordense". New Zealand Plant Conservation Network. Retrieved 12 September 2021.
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: CS1 maint: url-status (link) - "Assessment details for Dracophyllum fiordense W.R.B.Oliv". New Zealand Threat Classification System (NZTCS). Department of Conservation (New Zealand). 2017. Retrieved 12 September 2021.
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Books
- Mirza, Umair (2005). New Zealand Encyclopedia (6th Edition). New Zealand: David Bateman. ISBN 1869536010 – via the Internet Archive.
- Eagle, Audrey (2006). Eagle's complete trees and shrubs of New Zealand. Vol. 2. New Zealand: Te Papa Press. ISBN 0-909010-08-0.
- Venter, Stephanus (2009). A Taxonomic Revision of the Genus Dracophyllum Labill. (Ericaceae) (Thesis). Unpublished.