Orites acicularis | |
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Orites acicularis in sub-alpine habitat on Mount Wellington, Tasmania. | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Order: | Proteales |
Family: | Proteaceae |
Genus: | Orites |
Species: | O. acicularis |
Binomial name | |
Orites acicularis (R.Br.) Roem. & Schult. | |
Synonyms | |
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Orites acicularis, commonly known as yellow bush, is an angiosperm endemic to Tasmania, Australia and is a member of the genus Orites within the family Proteaceae. The species was first described in 1810 by Scottish botanist Robert Brown in Transactions of the Linnean Society of London. [1]
Orites acicularis is a yellow-green coloured, woody, rounded shrub growing to approximately 1–1.5 m (3.28–4.92 ft) in height and 0.5–1 m (1.64–3.28 ft) in width, with many ascending branches. [2]
The leaves are of a conspicuous yellow-green colour; they are glabrous, sclerophyllous, approximately 10-35mm long, and rounded. [3] They taper to a sharp point, which is typically more yellow than the rest of the leaf. The adaxial surface of the leaf has a shallow central groove, [4] and the leaf margins are entire. Leaves attach to the woody stem by a 2–5 mm petiole. [3]
Flowering occurs in December, and presents upon a rachis which can be terminal or axillary. The perianth is homochlamydeous; it comprises four white-cream tepals with a groove running along the centre, and curling under to display the pink style. [3] The immature fruit is a green similar to that of the leaves. The fruits are glabrous and oblong, with an elongated tip of reddish brown. When mature, the follicle is lignified and erect, approximately 15 mm long, and boat-shaped. [3] The boat shape is due to the seeds having been released immediately upon maturity. [2] [3]
Orites acicularis commonly occurs in Tasmanian sub-alpine mountain plateaus, heaths, and boulder fields with a geology of dolerite, granite, and diorite. [3] Dolerite's slow rate of erosion results in shallow, low-nutrient soils with an abundance of rock fragments. In sub-alpine plateaus, depressions form in the boulder fields.[ why? ] There, vegetable and mineral matter accumulate, creating bogs or smaller areas of deep soil. Similarly, bolster heath impedes drainage, creating shallow peats. [5]
Other species of plants that commonly grow in this habitat include: Gleichenia alpina , Astelia alpina , Baeckea gunniana , Bauera rubioides , Orites revoluta , Richea sprengelioides , Tasmannia lanceolata , and Eucalyptus coccifera .
Orites acicularis has evolved a number of characteristics to assist with protection from solar radiation in excess of its photosynthetic requirements. Two such adaptations are its abaxial pseudohypodermis and its bundle sheath extensions. [6]
Bundle sheath extensions are formed when sclerenchyma and/or collenchyma cells around a bundle sheath extend to both the adaxial and abaxial epidermis layers of a leaf. [7] The evolution of these bundle sheath extensions in species restricted to open vegetation in the family Proteaceae suggests that it is a recurring adaptation to provide protection against the high levels of solar radiation present. [6] The Orites-type abaxial pseudohypodermis is defined as multiseriate, elongate sclerids forming a reticulum around the sub-stomatal cavities (Jordan et al. 2005) and acts as a further barrier to solar radiation that lies just below the cuticle of the plant. [6]
The specific epithet, acicularis, is derived from Latin and means "needle-shaped". [8]
Hartz Mountains National Park is located in the south of Tasmania, Australia. It is one of 19 Tasmanian National Parks, and in 1989 it was included in the Tasmanian Wilderness World Heritage Area, in recognition of its natural and cultural values. The Hartz Mountains were named after the Harz mountain range in Germany.
The Tasmanian temperate rain forests are a temperate broadleaf and mixed forests ecoregion in western Tasmania. The ecoregion is part of the Australasian realm, which includes Tasmania and Australia, New Zealand, New Guinea, New Caledonia, and adjacent islands.
Orites is a genus of 9 known species, 7 endemic to Australia and 2 in South America; 1 in the Chilean Andes and 1 in Bolivia.
Eucalyptus coccifera, commonly known as the Tasmanian snow gum, is a small to medium-sized tree endemic to Tasmania. It has smooth, grey and cream-coloured bark, elliptic to lance-shaped adult leaves, flower buds in groups of between three and nine, usually white flowers and conical, hemispherical or cup-shaped fruit.
Ewartia planchonii, commonly known as creeping cushionherb, is an endemic herb to alpine areas of Tasmania. E. planchonii is commonly found in the western highlands of Tasmania. The Ewartia genus is described as cushion plants/herbs due to the characteristic growth habits of low growing, highly compact mats which are made up of highly packed stems. These mats are slow-growing and are often located in soils that contain low nutrients.
Orites revolutus , also known as narrow-leaf orites, is a Tasmanian endemic plant species in the family Proteaceae. Scottish botanist Robert Brown formally described the species in Transactions of the Linnean Society of London in 1810 from a specimen collected at Lake St Clair. Abundant in alpine and subalpine heath, it is a small to medium shrub 0.5 to 1.5 m tall, with relatively small, blunt leaves with strongly revolute margins. The white flowers grow on terminal spikes during summer. Being proteaceaous, O. revolutus is likely to provide a substantial food source for nectivorous animal species within its range.
Gleichenia alpina, commonly known as alpine coral-fern, is a small fern species that occurs in Tasmania and New Zealand. It grows in alpine and subalpine areas with moist soils and is a part of the Gleichrniaceae family.
Pomaderris apetala is a small tree or large shrub from the family Rhamnaceae, growing in Victoria, New Zealand and Tasmania.
Alpine vegetation refers to the zone of vegetation between the altitudinal limit for tree growth and the nival zone. Alpine zones in Tasmania can be difficult to classify owing to Tasmania's maritime climate limiting snow lie to short periods and the presence of a tree line that is not clearly defined.
Eucalyptus pulchella, commonly known as the white peppermint or narrow-leaved peppermint, is a species of small to medium-sized tree that is endemic to Tasmania. it has smooth bark, sometimes with rough fibrous bark on older trees, linear leaves, flower buds in groups of nine to twenty or more, white flowers and cup-shaped to shortened spherical fruit.
Astelia alpina called pineapple grass, silver astelia, or perching lily is a commonly found species in alpine and subalpine areas of Tasmania and the Australian Alps. It is a perennial herb that typically dominates its environment by growing in dense clusters, called mats, in alpine bogs. There are two subspecies: Astelia alpina var. novae hollandiae from New South Wales and Victoria and Astelia alpina var. alpina endemic to Tasmania. Both subspecies appear very similar to each other. The species was originally described by Robert Brown.
Trochocarpa thymifolia is a species of flowering plant from the family Ericacae and is endemic to Tasmania. It is a widespread alpine and subalpine shrub with small leaves, pink to red flowers and blue to purple fruit. Originally described by botanist Robert Brown in 1810, it is a widespread Tasmanian endemic that inhabits the state's mountain regions.
Pimelea sericea is a species of shrub in the family Thymelaeaceae. It is native to Australia, specifically Tasmania. Their common name is mountain rice flower. Pimelea means fat and sericea means silk. The reason could be that Pimelea species usually have oily seeds and fleshy cotyledon. The sericea came from the fact that they are covered with silky hair.
Orites diversifolia (=diversifolius), commonly known as variable orites, is a member of the family Proteaceae and is endemic to Tasmania. The common name stems from the variable form of the leaves, which range from entire and linear to serrated and ovate. It is a common shrub in lowland rainforest, subalpine woodland and scrub.
Pherosphaera hookeriana, or Mount Mawson pine, is a dwarf conifer endemic to Tasmania, at altitudes above 600 meters. There are roughly 30 known sites, with population numbers in the tens of thousands. The species occurs in a range of habitats typically in areas near water bodies, mostly on dolerite derived soils. The species is highly fire sensitive and an increase in fire events associated with climate change may lead to local extinction and fragmentation of habitat.
Cotula alpina, also known as the alpine cotula, is a perennial herb in the family Asteraceae. It is a small flowering plant that forms ground covering mats and is well adapted to alpine environments.
Carpha alpina, commonly known as small flower-rush, is a tufted perennial sedge from the family Cyperaceae. It is found primarily in south-east Australia and both islands of New Zealand, but also in Papua New Guinea.
Olearia ledifolia, commonly known as rock daisy bush, is a species of flowering plant of the family Asteraceae. It is endemic to Tasmania and found at higher altitudes where it grows as a low, compact bush with tough, leathery leaves and small white and yellow daisy-like "flowers" in summer.
Bedfordia salicina, commonly known as Tasmanian blanketleaf, is an endemic angiosperm of Tasmania, Australia. It is widespread throughout wet sclerophyll forests, moist gullies and intermediate forests and woodlands between wet and dry sclerophyll communities. Bedfordia salicina is abundant at low elevations, on dolerite, sandstone and mudstone substrate, east of Tylers line. Alternating leaves droop down to blanket the stem, coining the species common name, blanketleaf.
Anemone crassifolia, commonly known as mountain anemone, is a perennial herb in the family Ranunculaceae and is endemic to Tasmania, Australia. The species is common in high alpine moorlands of western and southern Tasmania at approximately 1000m. It is the only representative of the genus Anemone found in Australia.