Biology:Hakea cygna
| Hakea cygna | |
|---|---|
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| Hakea cygna subsp. cygna near Tathra National Park | |
Scientific classification 
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| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Order: | Proteales |
| Family: | Proteaceae |
| Genus: | Hakea |
| Species: | H. cygna
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| Binomial name | |
| Hakea cygna Lamont[1]
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| Occurrence data from Australasian Virtual Herbarium | |
Hakea cygna, commonly known as the swan hakea,[2] is usually a dense shrub endemic to Western Australia with creamy-white upright flowers appearing from July to August.
Description
Hakea cygna is an upright non-lignotuberous shrub growing to 0.4–2 m (1–7 ft) high. The smaller branches are densely covered in flattened silky hairs at flowering time. The leaves are variable, they may be flat and thick, narrowly egg-shaped widest in the middle, more or less needle-shaped or triangular in cross-section. Leaves are smooth 2–7.5 cm (0.79–3.0 in) long and 1.2–9 mm (0.047–0.35 in) wide with prominent veins on the leaf margin. The upper side of the leaves has 1-3 obscure longitudinal veins, the underside veins barely visible. The inflorescence consists of 6-14 creamy-white flowers in racemes, appearing upright and singly in leaf axils. The cream-white pedicels are smooth, rarely with soft short flattened hairs. The perianth a cream-white and the style is 5.5–7 mm (0.22–0.28 in) long. The oval to egg-shaped fruit are 2.1–3.7 cm (0.83–1.5 in) long and 1.2–2 cm (0.47–0.79 in) wide growing at an angle on a short thick stalk. The fruit is barely beaked but has a short prominent point. The seed are pale brown with darker streaks are broadly egg-shaped to almost triangular or circular and 12–20 mm (0.47–0.79 in) long. Flowers appear either from May to June or August to September.[2][3][4][5][6]
Taxonomy and naming
Hakea cygna was first formally described by Byron Barnard Lamont in 1987 and published in the Botanical Journal of the Linnean Society.[1] The specific epithet (cygna) is derived from the Latin word cygnus meaning "swan",[2][7] referring to the shape of the fruit believed to resemble that of a swan. Two subspecies of Hakea cygna have been recognised.
- Hakea cygna subsp. cygna has flat, thick, linear to narrowly egg-shaped leaves 2.5–9 mm (0.098–0.35 in) wide. Restricted to an area south of Lake King.
- Hakea cygna subsp. needlei has variable leaves either narrowly linear, needle-shaped or triangular in cross-section and 1.2–2 mm (0.047–0.079 in) wide.
Distribution and habitat
Hakea cygna is widely distributed from Geraldton to Ravensthorpe in the south-east and east to Cape Arid. It grows in heath or mallee-heath on gravelly loams, sandy loams, white yellow or grey sand, often over laterite.[3]
- Subspecies cygna is widespread from Eneabba in the north to the wheatbelt region of Western Australia to Merredin and south to Esperance.[2][3]
- Subspecies needlei has a restricted distribution with scattered populations just south of Lake King and in the Pallarup Nature Reserve.[2][3]
Conservation status
Hakea cygna subsp. needlei is classified as "Priority Two" by the Western Australian Government Department of Parks and Wildlife[5] meaning that it is poorly known and from only one or a few locations.[8]
References
- ↑ 1.0 1.1 "Hakea cygna". Australian National Herbarium. https://biodiversity.org.au/nsl/services/search?product=APNI&tree.id=&name=Hakea+cygna&inc._scientific=&inc.scientific=on&inc._cultivar=&inc._other=&max=100&display=apni&search=true.
- ↑ 2.0 2.1 2.2 2.3 2.4 Young, Jennifer (2006). "Hakeas of Western Australia:A Field and Identification Guide". J A Young. ISBN 0-9585778-2-X.
- ↑ 3.0 3.1 3.2 3.3 Wilson (ed), Annette; Barker, Robyn M.; Haegi, Laurence A.; Barker, William R. (1999). "Flora of Australia" Volume 17B Proteaceae 3 Hakeas to Dryandra. Canberra/Melbourne: ABRS-Department of Environment & Heritage. ISBN 0-643-06454-0. http://www.environment.gov.au/system/files/pages/6d8c5c3b-8545-437e-b9b3-944ac95ee07a/files/flora-australia-17b-proteaceae-3-hakea-dryandra.pdf.
- ↑ Holliday, Ivan (2005). "Hakeas a Field and Garden Guide". Reed New Holland. ISBN 1-877069-14-0.
- ↑ 5.0 5.1 "Hakea cygna". Western Australian Government. https://florabase.dpaw.wa.gov.au/browse/profile/2153.
- ↑ Archer, William (9 March 2012). "Hakea cygna". http://esperancewildflowers.blogspot.com/2012/03/hakea-cygna-subsp-cygna-swan-fruit.html.
- ↑ Brown, Roland Wilbur (1956). The Composition of Scientific Words. Washington, D.C.: Smithsonian Institution Press. p. 248.
- ↑ "Conservation codes for Western Australian Flora and Fauna". Government of Western Australia Department of Parks and Wildlife. https://www.dpaw.wa.gov.au/images/documents/plants-animals/threatened-species/Listings/Conservation%20code%20definitions.pdf.
Wikidata ☰ Q5640380 entry
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