Azorella polaris | |
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Azorella polaris on Campbell Island | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Asterids |
Order: | Apiales |
Family: | Apiaceae |
Genus: | Azorella |
Species: | A. polaris |
Binomial name | |
Azorella polaris (Hombr. & Jacquinot) G.M.Plunkett & A.N.Nicolas (2016) [1] | |
Synonyms [1] | |
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Azorella polaris, commonly known as the Macquarie Island cabbage, is a species of flowering plant usually placed in the family Araliaceae or Apiaceae and only very distantly related to cabbage. It is a megaherb, growing up to about a metre in height, native to the subantarctic islands of New Zealand and to Australia’s Macquarie Island.
Azorella polaris is a species of flowering plant in the family Apiaceae. [2] A plate of Azorella polaris (Hombr. & Jacq.) G. M. Plunkett & A. N. Nicolas was published in 1843 as Aralia polaris by French naturalist Jacques Bernard Hombron and Dutch botanist Nikolaus Joseph von Jacquin. [3] But they did not provide a description. The original description of the species was provided by Joseph Dalton Hooker in his Flora Antarctica in 1844. [4] [3] The species was transferred to the genus Stilbocarpa in 1854 by American botanist Asa Gray. Finally, in 2016, American botanists Gregory Plunkett and Antoine Nicolas transferred the species to the genus Azorella. [5]
Azorella polaris is closely related to two other subantarctic species, Azorella robusta and Azorella lyallii. [5] [6]
A. polaris was used as a food source and a scurvy preventative by early explorers and sealers. [7] [8] It was eaten by the survivors of the 1907 shipwreck of the Dundonald on Disappointment Island. [9] [8]
A. polaris is a large, herbaceous, rosette plant ("megaherb") up to 2 m tall and 2 m in diameter. It has branched stems and thick, fleshy rhizomes up to 4 cm thick. The leaves have long hairy petioles up to 60 cm long, and bright green, toothed leaf blades with prominent veins that are 20–35 cm long by 30–45 cm wide, suborbicular-reniform, fleshy, and very hairy with appressed hairs that are 1–2 cm long, or sometimes almost hairless on the underside. The flowers are arranged in compound, axillary and terminal umbels that can be up to 30 cm in diameter. The umbels are at the tips of hairy peduncles 10–15 cm long. Each flower is borne on a pedicel up to 1 cm long with entire bracts. The numerous flowers are about 5 mm wide, with waxy, yellow petals with a purple base. Fruits are subglobose, shiny, and 4–6 mm wide. [3] [10]
A. polaris has fruits mainly from November to February, but sometimes in October or March. [3]
Flowers are co-sexual, protandrous and dichogamous, meaning each umbel presents either stigmas or pollen. [11] There is only circumstantial evidence that the species is self-compatible. [11] Small flies are likely the pollinators. [11]
A. polaris is native to two subantarctic island groups of New Zealand, Campbell Island and Auckland Islands, as well as the Australian subantarctic island, Macquarie Island. [8]
On Macquarie Island, A. polaris is part of the dominant vegetation. [12] [13] Many species of myxomycetes were found on A. polaris and another megaherb, Pleruophyllum hookeri, as these species are the primary substrates available for slime moulds. [13]
It is classified as "At Risk - Naturally Uncommon" in the New Zealand threatened plants classification system, with the qualifiers CD (Conservation Dependent), PD (Partial Decline), RR (Range Restricted), SO (Secure Overseas). [14] [15]
Azorella polaris is extremely palatable and vulnerable to several introduced mammals to the subantarctic islands. [16] [7] [17] [18] Prior to the eradication of feral goats on Auckland Island, goat gut samples showed that Azorella polaris was one of the most palatable and preferred plants that the goats ate there, together with species of Anisotome and Pleurophyllum. [16] On Enderby Island, A. polaris was restricted to inaccessible cliffs but recovered to other areas of the island after cattle were removed. [17] Similarly, there was a significant recovery of A. poliaris and other subantarctic megaherbs and grasses in range, abundance, and individual plant size for subantarctic megaherbs on Campbell Island after sheep were removed. [18] On Macquarie Island, the species was threatened by introduced black rats and European rabbits, [7] until their eradication in 2011.
Apiaceae or Umbelliferae is a family of mostly aromatic flowering plants named after the type genus Apium, and commonly known as the celery, carrot or parsley family, or simply as umbellifers. It is the 16th-largest family of flowering plants, with more than 3,800 species in about 446 genera, including such well-known, and economically important plants as ajwain, angelica, anise, asafoetida, caraway, carrot, celery, chervil, coriander, cumin, dill, fennel, lovage, cow parsley, parsley, parsnip and sea holly, as well as silphium, a plant whose exact identity is unclear and may be extinct.
The Auckland Islands are an archipelago of New Zealand, lying 465 km (289 mi) south of the South Island. The main Auckland Island, occupying 460 km2 (180 sq mi), is surrounded by smaller Adams Island, Enderby Island, Disappointment Island, Ewing Island, Rose Island, Dundas Island, and Green Island, with a combined area of 570 km2 (220 sq mi). The islands have no permanent human inhabitants.
The Araliaceae are a family of flowering plants composed of about 43 genera and around 1500 species consisting of primarily woody plants and some herbaceous plants commonly called the ginseng family. The morphology of Araliaceae varies widely, but it is predominantly distinguishable based on its woody habit, tropical distribution, and the presence of simple umbels.
Macquarie Island is an island in the southwestern Pacific Ocean, about halfway between New Zealand and Antarctica. Regionally part of Oceania and politically a part of Tasmania, Australia, since 1900, it became a Tasmanian State Reserve in 1978 and was inscribed as a UNESCO World Heritage Site in 1997.
Pringlea antiscorbutica, commonly known as Kerguelen cabbage, is a flowering plant and the sole member of the monotypic genus Pringlea in the family Brassicaceae. Its common name comes from the archipelago of its discovery, the Kerguelen Islands, and its generic name derives from Sir John Pringle, president of the Royal Society at the time of its discovery by Captain James Cook's Surgeon, William Anderson in 1776.
Auckland Island is the main island of the eponymous uninhabited archipelago in the Pacific Ocean. It is part of the New Zealand subantarctic area. It is inscribed in the UNESCO World Heritage list together with the other New Zealand Subantarctic Islands in the region.
Azorella is a genus of flowering plants in the family Apiaceae, native to South America, New Zealand, southeastern Australia, and the islands of the Southern Ocean.
The Antarctic Floristic Kingdom, also the Holantarctic Kingdom, is a floristic kingdom that includes most areas of the world south of 40°S latitude. It was first identified by botanist Ronald Good, and later by Armen Takhtajan. The Antarctic Floristic Kingdom is a classification in phytogeography, different from the Antarctic realm classification in biogeography, and from Antarctic flora genera/species classifications in botany.
Azorella selago is a species of cushion plant native to the sub-Antarctic islands of the Southern Ocean, including the Crozet Islands, the Possession Islands, the Heard Island and McDonald Islands, the Kerguelen Islands, and the Prince Edward Islands. The closely related Azorella macquariensis, which is endemic to Macquarie Island, was split from it taxonomically in 1989. A. selago is often a keystone species where it occurs and is well studied for its contribution to its native ecosystems.
Taukihepa / Big South Cape Island is an offshore island of New Zealand to the west of the southern tip of Stewart Island / Rakiura. The island is the largest of the Tītī / Muttonbird Islands, and as such has no permanent inhabitants but is visited by muttonbirders in search of sooty shearwaters, known in New Zealand as "muttonbirds".
Azorella macquariensis, also known as Macquarie azorella or Macquarie cushions, is a species of cushion plant endemic to Australia’s subantarctic Macquarie Island. It was referred to the more widely distributed Azorella selago until 1989, when it was described as a separate species.
Pleurophyllum hookeri, also known as the silver-leaf daisy or sage-green rosette herb, is a herbaceous plant in the family Asteraceae, a megaherb native to the subantarctic Auckland and Campbell Islands of New Zealand and Australia’s Macquarie Island. It grows up to 900 mm in height and has crimson button flowers and long, silky, silver leaves, with a large carrot-like tuber and long roots. It also has the unusual feature of a vertically contractile stem, most of which is underground, which serves to keep the leaf rosette close to the ground surface and the plant anchored securely against the very strong winds typical of subantarctic islands. Prior to the successful eradication of introduced mammals on Macquarie Island in 2011, it had been threatened there by black rats and European rabbits.
Poa foliosa is a species of tussock grass commonly known as muttonbird poa. It is native to the subantarctic islands of New Zealand and Australia.
Anisotome latifolia, commonly known as the Campbell Island carrot, is a species of plant in the genus Anisotome of the carrot family (Apiaceae). It is native to the Auckland and Campbell Islands in the subantarctic regions of the South Pacific.
Aciphylla aurea, known as taramea in Māori and golden speargrass or golden Spaniard in New Zealand English, is a large, spiky, tufted plant with sharp yellowish-green leaves in the speargrass genus Aciphylla. A. aurea is found throughout the South Island of New Zealand in montane to low alpine habitats.
Azorella schizeilema is a species of cushion plant in the Apiaceae family, native to the Auckland and Campbell Islands.
Plantago brownii is a species of flowering plant in the family Plantaginaceae that is native to Tasmania, Australia and the subantarctic Auckland Islands of New Zealand. Robert Brown described the species in 1810, as P. carnosa R.Br. Plants of this species of plantain are annual or perennial with a rosette habit, fleshy toothed leaves, and short inflorescences.
Dichosciadium ranunculaceum is a monotypic genus of flowering plants belonging to the family Apiaceae. It is a small, flat perennial1 herb that can grow up to 20 cm wide. The species is commonly referred to as Wreath Pennywort.
Megaherbs are a group of herbaceous wildflowers growing in the New Zealand subantarctic islands and on the other subantarctic islands. They are characterised by their great size, with huge leaves and very large and often unusually coloured flowers, which have evolved as an adaptation to the harsh weather conditions on the islands. They suffer from overgrazing due to introduced mammals.
Azorella monteroi is a species of flowering plant in the family Apiaceae. It is endemic to southern Chile in the Biobío and Araucanía regions.