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Hakea is a genus of about 150 species of plants in the Family Proteaceae and are 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.

Hakea
Hakea laurina Tas.jpg
Hakea laurina (pin-cushion hakea)
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
Order: Proteales
Family: Proteaceae
Subfamily: Grevilleoideae
Genus: Hakea
Type species
Hakea teretifolia
Species

See text

Contents

DescriptionEdit

Plants in the genus Hakea are shrubs or small trees. Some species have flat leaves, whilst others have leaves which are needle-like, in which case they are sometimes divided and sometimes have a groove on the lower surface. The flowers are arranged in groups in leaf axils and are surrounded by bracts when in bud. The flowers have both male and female parts and are borne on a short stalk called a pedicel. The sepals and petals, jointly called tepals, form a curved tube which somtimes splits open as the flower develops. The style is longer than the tepal tube and is curved before its tip is released. When released, the tip of the style is a pollen-presenter. The fruit of hakeas is woody and persists on the plant until burned in a bushfire or until the plant dies. The fruit then splits open to release two winged seeds.[3][4][5][6]

Many species of hakea are similar to species of Grevillea but are distinguished from them in having persistent, woody fruits. (Those of grevilleas are not persistent and not woody. The upper and lower surfaces of the leaves of hakeas are similar (dissimilar in grevilleas), and the ovary and style are glabrous (hairy in grevilleas).[3]

Taxonomy and namingEdit

The genus Hakea was first formally described in 1798 by Heinrich Schrader and Johann Christoph Wendland and the description was published in Sertum Hannoveranum.[1][2] The genus is named after Baron Christian Ludwig von Hake, an 18th-century German patron of botany.[7][8]

DistributionEdit

Species of hakea are found in all states of Australia.[3]

HorticultureEdit

Hakeas are popular ornamental plants in gardens in Australia, and in many locations are as common as grevilleas and banksias. Several hybrids and cultivars have been developed. They are best grown in beds of light soil which are watered but still well drained.

Some showy western species, such as Hakea multilineata, H. francisiana and H. bucculenta, require grafting onto hardy stock such as Hakea salicifolia for growing in more humid climates, as they are sensitive to dieback.

Many species, particularly eastern Australian species, are notable for their hardiness, to the point they have become weedy. Hakea gibbosa, H. sericea, and H. drupacea (previously H. suaveolens) have been weeds in South Africa,[9][10][11] Hakea laurina has become naturalized in the eastern states of Australia and is considered an environmental weed,[12] and Hakea salicifolia, Hakea gibbosa, and Hakea sericea are invasive weeds in New Zealand.[13][14][15]

 
Hakea epiglottis
 
Hakea decurrens ssp. physocarpa

List of speciesEdit

The following is a list of Hakea species recognised by the Australian Plant Census, except for Hakea asperma which is recognised by the Royal Botanic Gardens Victoria:[16][17]

ReferencesEdit

  1. ^ a b "Hakea". APNI. Retrieved 3 November 2018.
  2. ^ a b Schrader, H.A. & Wendland, J.C. (1798), Sertum Hannoveranum 3: 27, t. 17
  3. ^ a b c Barker, Robyn Mary; Harden, Gwen J.; Haegi, Laurence Arnold Robert; Barker, William Robert. "Genus Hakea". Royal Botanic Garden Sydney. Retrieved 3 November 2018.
  4. ^ "Hakea". Royal Botanic Gardens Victoria. Retrieved 3 November 2018.
  5. ^ "Hakea". Western Australian Herbarium. Retrieved 3 November 2018.
  6. ^ "Hakea". State Herbarium of South Australia. Retrieved 3 November 2018.
  7. ^ "Hakea propinqua". Australian National Botanic Gardens. Retrieved 3 November 2018.
  8. ^ "Hakea costata". Australian Native Plants Society, Australia. Retrieved 3 November 2018.
  9. ^ "Invasive Weeds Compendium Hakea sericea". CABI. Retrieved 12 July 2018.
  10. ^ "Weed Risk Assessment for Hakea gibbosa (Sm.) Cav. (Proteaceae) – Rock hakea" (PDF). CABI. USDA. 2012. Retrieved 12 July 2018.
  11. ^ "Invasive species compendium Hakea drupacea sweet hakea". CABI. Retrieved 12 July 2018.
  12. ^ "Weeds of Australia Factsheet Hakea laurina". Biosecurity Queensland Edition. Queensland Government. Retrieved 12 July 2018.
  13. ^ "Flora of New Zealand Hakea sericea Schrad. & J.C.Wendl". Landcare Research Manaaki Whenua.
  14. ^ "Flora of New Zealand Hakea gibbosa Cav". Landcare Research Manaaki Whenua.
  15. ^ "Flora of New Zealand Hakea salicifolia (Vent.) B.L.Burtt". Landcare Research Manaaki Whenua.
  16. ^ "Hakea". Australian National Botanic Gardens. Retrieved 3 November 2018.
  17. ^ Messina, Andre; Walsh, Neville. "Hakea asperma". Royal Botanic Gardens Victoria. Retrieved 3 November 2018.

Further readingEdit

  • Barker WR, Barker RM, Haegi L (1999). "Hakea". In Wilson, Annette. Flora of Australia: Volume 17B: Proteaceae 3: Hakea to Dryandra. CSIRO Publishing / Australian Biological Resources Study. pp. 1&ndash, 170. ISBN 0-643-06454-0.
  • Holliday Ivan (2005). Hakeas:a field and garden guide. Reed New Holland. ISBN 1-877069-14-0.
  • Young, JA (2006). Hakeas of Western Australia : a field and identification guide. ISBN 978-0-9585778-2-3.

External linksEdit