Hakea constablei

Family: Proteaceae

A compact to open rounded shrub to small tree, growing potentially to 7 metres tall. The new growth is very hairy.

It is endemic to an area in the Blue Mountains and Wollondilly catchment in NSW; one patch is from just south of Katoomba, north to Bilpin and west to Lithgow, with other occurrences at Lake Burragorang and to the south towards Wombeyan Caves.

It is found on higher sandstone outcrops, in dry sclerophyll forests and woodland.

Leaves to 12 cm long and only 0.2 cm in diameter, with a mucro to 2 mm long, and overall tubular (terete / needle-leaf), dark to mid green. The leaves are not particularly prickly but are clustered heavily on the stems.

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, the inflorescences occur as loose clusters on the previous season’s stems, with up to 12 flowers per cluster, to 20 mm long by 40 mm wide, cream-white in colour, primarily from September 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.

The carpels are to 20 mm long, white-cream in colour. The perianths are also white-cream. The follicles are dark brown, almost round, to 55 mm long, and to 40 mm wide, covered in warty protuberances and not strongly beaked. Seeds have one wing.

In the garden

A rare plant in the wild but it has a history of being sold and cultivated with much success. It is reported by Wrigley and Fagg (see resources) to be one of the most- hardy needle-leaf hakeas to grow. It prefers a well-draining sandy soil but may tolerate heavier soils. Can be pruned and kept low and dense. Creates dense bird habitat and foraging opportunities. Flowers are bird and butterfly attracting.

This plant is also grown for the beautiful fruit-ripening process. There is anecdotal evidence that the seed take two years to ripen within fruits.

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, including ‘Burrendong Beauty’. They are best grown in beds of light soil, which are watered but still well-drained.

Propagation

Likely from seed which is available commercially.

Other information

Hakea is a genus of about 150 species of plants that are endemic to Australia. Was first described in 1788 by Joseph Gaertner, a German botanist.

Likely regenerates from seed 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).

constablei – honours Ernie Constable (1903-1986), a former seed and plant collector for the Royal Botanic Gardens in Sydney and after whom several species are named. He collected the type specimen for this species.

Hakea constablei is considered a rare species on the ROTAP list (Rare or Threatened Australian Plants) – Briggs, Leigh and Hartley, 1996.

It is not currently listed legally as threatened with extinction.

https://en.wikipedia.org/wiki/Hakea

https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Hakea~constablei

https://apps.lucidcentral.org/plants_se_nsw/text/entities/hakea_constablei.htm

Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping, 4th edition. New Holland Publishers Pty Ltd Australia.

By Jeff Howes, edited by Dan Clarke