''Azorella polaris'', commonly known as the Macquarie Island cabbage, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

usually placed in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Araliaceae 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 ...

Apiaceae 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 p ...

and only very distantly related to

cabbage Cabbage, comprising several cultivars of '' Brassica oleracea'', is a leafy green, red (purple), or white (pale green) biennial plant grown as an annual vegetable crop for its dense-leaved heads. It is descended from the wild cabbage ( ''B.& ...

. It is a

megaherb 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 ...

, growing up to about a metre in height, native to the

subantarctic The sub-Antarctic zone is a physiographic region in the Southern Hemisphere, located immediately north of the Antarctic region. This translates roughly to a latitude of between 46th parallel south, 46° and 60th parallel south, 60° south of t ...

islands of New Zealand and to Australia's

Macquarie Island Macquarie Island is a subantarctic island in the south-western Pacific Ocean, about halfway between New Zealand and Antarctica. It has been governed as a part of Tasmania, Australia, since 1880. It became a Protected areas of Tasmania, Tasmania ...

Taxonomy

''Azorella polaris'' is a species of flowering plant in the family

. 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 Jacques Bernard Hombron (1798–1852) was a French naval surgeon and naturalist. Hombron served on the French voyage of the ''Astrolabe'' and ''Zélée'' between 1837 and 1840 to investigate the perimeter of Antarctica. He described a number of pl ...

and Dutch botanist

Nikolaus Joseph von Jacquin Nikolaus Joseph Freiherr von Jacquin (16 February 172726 October 1817) was a scientist who studied medicine, chemistry and botany. Biography Born in Leiden in the Netherlands, he studied medicine at Leiden University, then moved first to Par ...

. But they did not provide a description. The original description of the species was provided by

Joseph Dalton Hooker Sir Joseph Dalton Hooker (30 June 1817 – 10 December 1911) was a British botanist and explorer in the 19th century. He was a founder of geographical botany and Charles Darwin's closest friend. For 20 years he served as director of the Ro ...

in his ''

Flora Antarctica The ''Flora Antarctica'', or formally and correctly ''The Botany of the Antarctic Voyage of H.M. Discovery Ships Erebus and Terror in the years 1839–1843, under the Command of Captain Sir James Clark Ross'', is a description of the many plants ...

'' in 1844. The species was transferred to the genus '' Stilbocarpa'' in 1854 by American botanist

Asa Gray Asa Gray (November 18, 1810 – January 30, 1888) is considered the most important American botany, botanist of the 19th century. His ''Darwiniana'' (1876) was considered an important explanation of how religion and science were not necessaril ...

. Finally, in 2016, American botanists Gregory Plunkett and Antoine Nicolas transferred the species to the genus ''

Azorella ''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. They are low-growing dwarf mat-forming plants growing in high exposure on mo ...

.'' ''Azorella polaris'' is closely related to two other subantarctic species, '' Azorella robusta'' and '' Azorella lyallii.''

Description

''A. polaris'' is a large, herbaceous, rosette plant ("

") up to 2 m tall and 2 m in diameter. It has branched stems and thick, fleshy

rhizomes In botany and dendrology, a rhizome ( ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...

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 UMBEL (Upper Mapping and Binding Exchange Layer) is a logically organized knowledge graph of 34,000 concepts and entity types that can be used in information science for relating information from disparate sources to one another. It was retired ...

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 Pedicle or pedicel may refer to: Human anatomy *Pedicle of vertebral arch, the segment between the transverse process and the vertebral body, and is often used as a radiographic marker and entry point in vertebroplasty and kyphoplasty procedures ...

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. ''A. polaris'' has fruits mainly from November to February, but sometimes in October or March.

Breeding system

Flowers are co-sexual,

protandrous Sequential hermaphroditism (called dichogamy in botany) is one of the two types of hermaphroditism, the other type being simultaneous hermaphroditism. It occurs when the organism's sex changes at some point in its life. A sequential hermaphrodit ...

and dichogamous, meaning each umbel presents either stigmas or pollen. There is only circumstantial evidence that the species is self-compatible. Small flies are likely the pollinators.

Distribution and habitat

''A. polaris'' is native to two subantarctic island groups of New Zealand, Campbell Island and

Auckland Islands The Auckland Islands ( Māori: ''Motu Maha'' "Many islands" or ''Maungahuka'' "Snowy mountains") are an archipelago of New Zealand, lying south of the South Island. The main Auckland Island, occupying , is surrounded by smaller Adams Island ...

, as well as the Australian subantarctic island,

. On Macquarie Island, ''A. polaris'' is part of the dominant vegetation. 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.

Relationship with humans

''A. polaris'' was used as a food source and a

scurvy Scurvy is a deficiency disease (state of malnutrition) resulting from a lack of vitamin C (ascorbic acid). Early symptoms of deficiency include weakness, fatigue, and sore arms and legs. Without treatment, anemia, decreased red blood cells, gum d ...

preventative by early

explorers Exploration is the process of exploring, an activity which has some expectation of discovery. Organised exploration is largely a human activity, but exploratory activity is common to most organisms capable of directed locomotion and the abilit ...

and

sealers Sealer may refer either to a person or ship engaged in seal hunting, or to a sealant; associated terms include: Seal hunting * Sealer Hill, South Shetland Islands, Antarctica * Sealers' Oven, bread oven of mud and stone built by sealers around 1800 ...

. It was eaten by the survivors of the 1907 shipwreck of the ''

Dundonald Dundonald may refer to: Places Canada * Dundonald, Ontario, Cramahe * Dundonald, Saskatoon, Saskatchewan * Dundonald Park, in Ottawa South Africa * Dundonald, Mpumalanga United Kingdom * Dundonald, County Down, Northern Ireland ** Dundonald ...

'' on

Disappointment Island Disappointment Island is one of seven uninhabited islands in the Auckland Islands archipelago, in New Zealand. It is south of the country's main South Island and from the northwest end of Auckland Island. It is home to a large colony of whi ...

Conservation status

It is classified as "At Risk — Naturally Uncommon" in the

New Zealand Threat Classification System The New Zealand Threat Classification System is used by the Department of Conservation to assess conservation priorities of species in New Zealand. The system was developed because the IUCN Red List, a similar conservation status system, had s ...

, with the qualifiers CD (Conservation Dependent), PD (Partial Decline), RR (Range Restricted), SO (Secure Overseas). Azorella polaris 319805203

''Azorella polaris'' is extremely palatable and vulnerable to several introduced mammals to the subantarctic islands. Prior to the eradication of feral goats on

Auckland Island 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 Subant ...

, 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 ''Pleurophyllum'' is a genus of subantarctic plants in the tribe Astereae within the family Asteraceae.Hooker, Joseph Dalton. 1844. Botany of the Antarctic Voyage ...Volume 1. Flora Antarctica page 30. ''Pleurophyllum'' is native to the subanta ...

.'' On

Enderby Island Enderby Island is part of New Zealand's uninhabited Auckland Islands archipelago, south of mainland New Zealand. It is situated just off the northern tip of Auckland Island, the largest island in the archipelago. Geography and geology Enderby ...

, ''A. polaris'' was restricted to inaccessible cliffs but recovered to other areas of the island after cattle were removed. 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. On Macquarie Island, the species was threatened by introduced

black rat The black rat (''Rattus rattus''), also known as the roof rat, ship rat, or house rat, is a common long-tailed rodent of the stereotypical rat genus ''Rattus'', in the subfamily Murinae. It likely originated in the Indian subcontinent, but is n ...

s and

European rabbit The European rabbit (''Oryctolagus cuniculus'') or coney is a species of rabbit native to the Iberian Peninsula (Spain, Portugal and Andorra) and southwestern France. It is the only extant species in the genus ''Oryctolagus''. The European rab ...

s, until their eradication in 2011.

References

External links

''Azorella polaris'' occurrence data from Australasian Virtual Herbarium
* ''Azorella polaris'' discussed on

RNZ Radio New Zealand (), commonly known as RNZ or Radio NZ, is a New Zealand public service broadcaster and Crown entity. Established under the Radio New Zealand Act 1995, it operates news and current affairs station, RNZ National, and a classica ...

Critter of the Week ''Critter of the Week'' is a weekly RNZ National programme about endangered and neglected native plants and animals of New Zealand. Beginning in 2015, ''Critter of the Week'' is an approximately 15-minute discussion between Nicola Toki (origi ...

''
12 July 2024
{{Taxonbar, from1=Q56603933, from2=Q3973531

polaris Polaris is a star in the northern circumpolar constellation of Ursa Minor. It is designated α Ursae Minoris (Latinisation of names, Latinized to ''Alpha Ursae Minoris'') and is commonly called the North Star or Pole Star. With an ...

Flora of New Zealand Flora of Macquarie Island Flora of the Campbell Islands Flora of the Auckland Islands Plants described in 1854