Orites acicularis

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Orites acicularis
Orites aciculatis title image Januarygirl.jpg
Orites acicularis in sub-alpine habitat on Mount Wellington, Tasmania.
Scientific classification Red Pencil Icon.png
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
  • Oritina acicularisR.Br.

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]

Contents

Description

Orites acicularis flower.jpg
Flowers
Orites acicularis seed pods 1.jpg
Immature fruit

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]

Habitat and distribution

Orites acicularis sub-alpine habitat.jpg
O. acicularis in sub-alpine plateau habitat on Mount Wellington, Tasmania
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Distribution map for Tasmania

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 .

Adaptations to solar radiation

Orites acicularis abaxial pseudohypodermis.jpg
Transverse section of leaf showing Orites-type abaxial pseudohypodermis (stained blue)
Orites acicularis bundle sheath extension.jpg
Transverse section of leaf showing the bundle sheath extension

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]

Etymology

The specific epithet, acicularis, is derived from Latin and means "needle-shaped". [8]

Related Research Articles

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<i>Orites</i> Genus of plants in the family Proteaceae

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.

<i>Eucalyptus coccifera</i> Species of eucalyptus

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.

<i>Ewartia planchonii</i> Species of flowering plant

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.

<i>Orites revolutus</i> Species of plant in the family Proteaceae endemic to Tasmania

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.

<i>Gleichenia alpina</i> Species of fern

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.

<i>Pomaderris apetala</i> Species of tree

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.

<i>Eucalyptus pulchella</i> Species of eucalyptus

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.

<i>Astelia alpina</i> Species of flowering plant

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.

<i>Trochocarpa thymifolia</i>

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.

<i>Pimelea sericea</i> Species of shrub

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.

<i>Orites diversifolia</i> Species of flowering plant

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.

<i>Pherosphaera hookeriana</i> Species of conifer

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.

<i>Cotula alpina</i> Species of flowering plant

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.

<i>Carpha alpina</i> Species of grass-like plant

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.

<i>Olearia ledifolia</i> Species of shrub

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.

<i>Bedfordia salicina</i> Species of flowering plant

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.

<i>Anemone crassifolia</i> Page created to represent a species of plant, not formerly represented on Wikipedia

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.

References

  1. "Vascular Plants APNI – Australian Plant Name Index". Biodiversity. Retrieved 2018-03-11.
  2. 1 2 Howells, Christine (2012). Tasmania's Natural Flora (2nd ed.). Hobart: Australian Plants Society Tasmania. ISBN   978-0-909830-66-3. OCLC   803605684.
  3. 1 2 3 4 5 6 "ABRS Flora of Australia Online Search Results". anbg.gov.au. Archived from the original on 2018-03-16. Retrieved 2018-03-05.
  4. Jordan, Greg. "Key to Tasmanian Vascular Plants". utas.edu.au. Retrieved 2018-03-11.
  5. Crowden, R. K. (2005). "Alpine Vegetation". Vegetation of Tasmania. Canberra: Australian Biological Resources Study. pp. 333–56. ISBN   978-0-646-44512-0.
  6. 1 2 3 Jordan, Gregory J.; Dillon, Rebecca A.; Weston, Peter H. (May 2005). "Solar radiation as a factor in the evolution of scleromorphic leaf anatomy in proteaceae". American Journal of Botany. 92 (5): 789–796. doi: 10.3732/ajb.92.5.789 . PMID   21652458 via Research Gate.
  7. Raven, Peter H.; Evert, Ray F.; Eichhorn, Susan E. (2005). Biology of Plants . New York: W.H. Freeman and Company Publishers. pp.  566. ISBN   0-7167-1007-2.
  8. Eggli, Urs; Newton, Leonard E. (2004). Etymological Dictionary of Succulent Plant Names. Berlin, Heidelberg: Springer. p. 1. ISBN   978-3-540-00489-9 . Retrieved 14 November 2018.