Hakea sericea, Silky Hakea or Needlebush, is a tall shrub reaching a height of 7 metres, often with a narrow spread of up to 2 metres, without a lignotuber.
It has a mostly coastal distribution in NSW, with the main distribution, north of Batemans Bay, but also with a disjunct occurrence on the far south coast around Eden. From the latter, and somewhat oddly, it spreads commonly through Victoria, through the eastern regions and in limited locations in the western regions (around Horsham). It also extends into South Australia, found between Horsham and Adelaide. From Batemans Bay, NSW, it extends northwards and as far west as Tarago and Bathurst, commonly to Newcastle, then with disjunct patches up to west of Caboolture in Queensland.
It can be found in heathland and shrubland as well as dry sclerophyll woodland and forest, on soils ranging from sandstone-derived tro shale-sandstone transition, as well as aluuvium and clay-loams.
Juvenile growth is light green with silky hairs hence the former common name. Adults leaves are alternate to spiral on stems, stiff, linear and narrow-tubular, to 70 mm long, but only 1 mm in diameter dark green and crowned with an extremely sharp point (hence the latter common name).
A hakea inflorescence is technically a cluster of paired flowers, termed a conflorescence (although sometimes the paired flowers are not evident) with the overall structure forming a clustered-raceme-like appearance. The inflorescences are always produced in the leaf axils, as opposed to the closely related Grevillea where they are mostly terminal. They can appear as a spider-flower-like cluster, or a rounded ball where flowers emerge around a 360° radius, or as a cylindrical raceme (which strongly resemble those of Grevillea).
In this species, flowers are white-cream and profuse, prodcued in axillary clusters of up to 7 flowers, often with inflorescences clustered together, and usually perfumed. Flowering extends from July to November. Individual flowers are composed of 1 carpel (female part) where the style and stigma protrude out; 4 stamens hidden away in the perianth; and the perianth (petals and sepals collectively) which connects to a pedicel. Proteaceae flowers do not have any discernible petals or sepals (having only one whorl) and so these are referred to as ‘tepals’ of which there are 4. In this species, the perianth and carpels are white-cream, with overall flowers about 10 mm long and very narrow.
The follicles are large, persistent and woody, to 35 mm long by 20 mm wide and deeply wrinkled, with a short beak. Each fruit contains the usual two winged seeds.
A very useful shrub that is known to be cultivated and sold, and also used effectively in bushland regeneration projects. It grows reliably on a well-drained soil in full sun to part shade.
It is very prickly so consider the location in terms of pedestrian traffic and any children using the garden. Useful for barrier-planting.
There is a pink form in cultivation.
Author’s notes: Harvesting the fruits is a painful process due to the prickly foliage. On the plus side the foliage provides safe shelter and nesting sites for small native birds. Double-barred finches frequently nest in our Silky Hakeas.
A clump of three or more Silky Hakeas would be a useful addition to bird-friendly gardens.
Propagate from seed.
The Silky Hakea has become a serious environmental weed in South Africa. It was introduced as a hedging plant in about 1858.
Hakea sericea was cultivated in England in the early 1800’s.
Hakea is a genus of about 150 species of plants that are endemic to Australia, first described in 1788 by Joseph Gaertner, a German botanist. NSW currently has about 31 species, some which are species-complex.
Hakeas 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 fruit of Hakea spp. generally persist on plants until burned in a bushfire or until the plant dies. The fruit then splits open to release two winged seeds. This species regenerates from seed after fire and can be observed in large seedling-numbers in some burnt areas after fire.
Hakea – named after Baron Christian Ludwig von Hake (Baron von Hake of Hanover, 1745-1818), an 18th-century German patron of botany (and for whom not a lot of information can be found).
sericea – Latin sericeus, meaning “silky”, referring to the silky hairs, mostly seen on juvenile foliage.
This species is not considered to be at risk of extinction in the wild.
NSW Flora Online (PlantNET) – Hakea sericea profile page https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Hakea~sericea
Australian National Herbarium – Hakea sericea profile page https://www.anbg.gov.au/gnp/gnp3/hakea-sericea.html
Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping. 4th edition. New Holland Publishers, Pty. Ltd. Australia.