Hakea aenigma

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Enigma hakea
Hakea aenigma.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Order: Proteales
Family: Proteaceae
Genus: Hakea
Species:
H. aenigma
Binomial name
Hakea aenigma
Hakea aenigmaDistMap4.png
Occurrence data from Australasian Virtual Herbarium

Hakea aenigma, commonly known as the enigma hakea, [3] is a critically endangered shrub in the family Proteaceae endemic to Kangaroo Island in South Australia. It is one of two Hakea species totally reliant on suckering to reproduce therefore having "reached evolutionary dead-ends" as this method of reproduction greatly limits genetic variation. The entire population of this species may be of clonal colonies descended from a single individual. [1]

Contents

Description

Hakea aenigma is a rounded bushy shrub 1.5 to 2.5 metres (4.9 to 8.2 ft) high. Smaller branches are densely covered with flattened fine hairs, thinning nearer flowering time. The glabrescent leaves are flat and linear 5 to 35 centimetres (2 to 14 in) long and 3 to 10 millimetres (0.1 to 0.4 in) wide with prominent longitudinal veins 1-7 above and 4-9 on the underside. Each inflorescence has 16-33 flowers growing on an individual stalk. Pedicels and perianth are cream-white and smooth. The style 4.5–7.2 mm (0.2–0.3 in) long. Flowers are sterile so no fruit is produced and plants can only reproduce vegetatively by suckering roots. Hakea pulvinifera is the only other species reliant on this method for reproduction. Hakea aenigma has cream-white blooms throughout spring from September to November. [4] [5]

Taxonomy and naming

Hakea aenigma was first formally described by the botanists Laurence Arnold Haegi and William Robert Barker in 1985 and the description was published in the Journal of the Adelaide Botanic Gardens. [6] [7] The specific epithet is taken from the Latin word aenigma meaning "riddle", "something obscure" or "inexplicable" [8] :302 referring to the puzzlement of finding no fruit for the plant and the uncertainty of its origins. [4]

Distribution

This species is endemic to a small area on the western end of Kangaroo Island in South Australia. It is confined to the more elevated parts of the lateritic plateu system, up to 100 metres above sea level and is part of the dense mallee-heath that grows in clay-loam to sandy soils. [1] [4]

Conservation status

Hakea aenigma is listed as "Critically endangered" on the IUCN Red List of Threatened Species due to the possibility of the entire population consisting of clonal colonies descended from a single individual. This results in little to no genetic variation which makes it more vulnerable to threats such as pathogens, climate change and possible increase in fire regimes. [1]

Related Research Articles

<i>Hakea</i> Genus of plants in the family Proteaceae endemic to Australia

Hakea is a genus of about 150 species of plants in the Family Proteaceae, endemic to Australia. They are shrubs or small trees with leaves that are sometimes flat, otherwise circular in cross section in which case they are sometimes divided. The flowers are usually arranged in groups in leaf axils and resemble those of other genera, especially Grevillea. Hakeas have woody fruit which distinguishes them from grevilleas which have non-woody fruit which release the seeds as they mature. Hakeas are found in every state of Australia with the highest species diversity being found in the south west of Western Australia.

<i>Hakea petiolaris</i> Species of plant in the family Proteaceae endemic to south West Australia

Hakea petiolaris, commonly known as the sea-urchin hakea, is a shrub or small tree with cream-coloured and pink or purple flowers and woody fruit. It is endemic to the south west of Australia, occurring at the coastal plain, jarrah forest and wheatbelt regions, often at the ancient granite outcrops of Western Australia.

<i>Hakea scoparia</i> Species of shrubin the family Proteaceae endemic to south-west Western Australia

Hakea scoparia is a species of flowering plant in the family Proteaceae and is endemic to the south-west of Western Australia where it grows in shrubland. It is a shrub with ascending branches, terete leaves and clusters of cream to pinkish flowers in leaf axils from June to September.

<i>Hakea teretifolia</i> Species of plant

Hakea teretifolia, commonly known as the dagger hakea, is a species of woody shrub of the family Proteaceae and is common on heathlands in coastal eastern Australia from northern New South Wales through to Victoria and Tasmania. A very prickly shrub, it is rarely cultivated but easy to grow.

<i>Hakea rugosa</i> Species of shrub of the family Proteaceae native to Australia

Hakea rugosa, commonly known as wrinkled hakea or dwarf hakea, is a shrub of the family Proteaceae native to Australia. It has sharp needle-shaped leaves and white or cream fragrant flowers in profusion from August to October.

<i>Hakea pulvinifera</i> Species of shrub in the family Proteaceae endemic to New South Wales, Australia

Hakea pulvinifera, also known as Lake Keepit Hakea, is a small, prickly shrub in the family Proteaceae, found only on one rocky hillside at Lake Keepit near Gunnedah in New South Wales, Australia. The species was first described in 1962, believed extinct in 1971 and rediscovered in 1988. The entire species may be of only one genetically unique individual. It is one of only two Hakea species that reproduce solely through basal shoots or 'suckering', reducing genetic variation.

<i>Hakea dohertyi</i> Species of plant in the family Proteaceae endemic to central New South Wales in Australia

Hakea dohertyi, commonly known as the Kowmung hakea, is a shrub endemic to a restricted locale in the Great Dividing Range in central New South Wales in Australia.

<i>Hakea mitchellii</i> Species of shrub in the family Proteaceae from South Australia and Victoria

Hakea mitchellii, commonly known as desert hakea, is a shrub species in the family Proteaceae.

<i>Hakea aculeata</i> Species of plant of the family Proteaceae found in Western Australia

Hakea aculeata, commonly known as the column hakea, is a vulnerable species of the family Proteaceae found in the Wheatbelt region of Western Australia. An unusual sculptural species with dense columns of prickly foliage and plentiful clusters of strongly scented blooms in spring.

Hakea acuminata is a shrub of the family Proteaceae native to Western Australia. A restricted species bearing clusters of white flowers with a green or pinkish tinge in late autumn to winter.

<i>Hakea bicornata</i> Species of shrub in the family Proteaceae native to Western Australia,

Hakea bicornata is a shrub in the family Proteaceae native to Western Australia, with attractive creamy-white flowers and fruit with two distinctive horns.

<i>Hakea brownii</i> Species of shrub in the family Proteaceae native to Western Australia

Hakea brownii commonly known fan-leaf hakea is a shrub in the family Proteaceae native to an area in the Wheatbelt region of Western Australia. This species shares a common name with Hakea baxteri due to its distinctive leaves.

<i>Hakea elliptica</i> Species of shrub in the family Proteacea endemic to Western Australia

Hakea elliptica, commonly known as the oval-leaf hakea, is a shrub in the family Proteacea and is endemic to Western Australia. A fast growing adaptable species with ornamental wavy leaves, golden bronze new growth and an abundance of showy white flowers. A good wildlife habitat due to its dense form with foliage to ground level.

<i>Hakea hastata</i> Species of shrub in the family Proteaceae endemic to southern Western Australia

Hakea hastata is a shrub in the family Proteaceae and is endemic to southern Western Australia. It is an open, upright shrub with light green leaves, branches covered in dense hairs and white flowers in spring.

<i>Hakea ilicifolia</i> Species of plant in the family Proteacea endemic to Western Australia

Hakea ilicifolia is an open shrub or tree in the family Proteacea and is endemic to Western Australia. It is a small, dense shrub with stiff, lobed leaves and clusters of yellow or creamy-white flowers.

<i>Hakea megalosperma</i> Species of shrub in the family Proteaceae endemic to Western Australia

Hakea megalosperma, commonly known as Lesueur hakea, is a shrub of the genus Hakea native to a small area along the west coast in the Wheatbelt region of Western Australia. It is a small shrub with sweetly fragrant white or pink flowers, darkening as they age to red and thick egg-shaped bluish-green leaves.

<i>Hakea meisneriana</i> Species of shrub in the family Proteaceae endemic to Western Australia

Hakea meisneriana is a shrub in the family Proteaceae and is endemic to Western Australia. It has small, nectar rich, creamy white flowers in clusters in the upper branches from August to November.

<i>Hakea obliqua</i> Species of shrub in the family Proteaceae endemic to Western Australia

Hakea obliqua, commonly known as needles and corks, is a shrub in the family Proteaceae and is endemic to an area in the Wheatbelt, Great Southern and Goldfields-Esperance regions of Western Australia.

<i>Hakea oldfieldii</i> Species of shrub of the family Proteaceae endemic to the South West region of Western Australia

Hakea oldfieldii is a shrub of the family Proteaceae and is endemic to South West region of Western Australia. It has small white or cream-yellow flowers in profusion in spring.

Hakea leucoptera subsp. sericipes is a small tree with cylinder-shaped leaves and clusters of up to forty-five white fragrant flowers. It is found in northwestern New South Wales, Queensland and Western Australia.

References

  1. 1 2 3 4 "Hakea aenigma". The IUCN Red List of Threatened Species. 2020. Retrieved 14 December 2023.
  2. Barker, William R.; Haegi, Laurence. "Hakea aenigma". Vascular Plants:APC. Australian Government. Retrieved 1 February 2019.
  3. "Hakea aenigma W.R.Barker & Haegi - Enigma Hakea". Atlas of Living Australia. Global Biodiversity Information Facility. Retrieved 11 June 2016.
  4. 1 2 3 "Factsheet - Hakea aenigma". Government of South Australia . Retrieved 11 June 2016.
  5. Barker, Robyn M.; Haegi, Laurence A.; Barker, William R. "Haekea aenigma". Flora of Australia. Australian Biological Resources Study, Department of Climate Change, Energy, the Environment and Water: Canberra. Retrieved 14 December 2023.
  6. "Hakea aenigma W.R.Barker & Haegi". Atlas of Living Australia. Global Biodiversity Information Facility . Retrieved 17 October 2018.
  7. Barker, W.R.; Haegi, L. (1985). "Taxonomy of the South Australian species allied to Hakea ulicina R.Br. (Proteaceae). Journal of the Adelaide Botanic Gardens 7(3): 261, fig. 7" (PDF).
  8. Brown, Roland Wilbur (1956). The Composition of Scientific Words. Washington, D.C.: Smithsonian Institution Press.