 Hakea laurina. Photo © W.R.Barker |
 Hakea bucculenta. Photo © W.R.Barker |
 Hakea corymbosa. Photo © W.R.Barker |
 Hakea tephrosperma. Photo © W.R.Barker |
 Hakea decurrens. Photo © W.R.Barker |
 Hakea eriantha. Photo © W.R.Barker |
 Hakea lissosperma. Photo © W.R.Barker |
Synonymy
Hakea Schrad. & J.C.Wendl., Sert. Hannov. 27 (Dec. 1797).
Type: H. glabra Schrad. & J.C.Wendl.
Conchium Sm., Trans. Linn. Soc. London 4: 215 (May 1798). T: not designated.
[Banksia auct. non L.f.: R.A.Salisbury, Prodr. Stirp. Chap. Allerton 51 (1796), p.p. as to Banksia teretifolia; J.E.Smith, in J.White, J. Voy.
[Lambertia auct. non Sm.: C.F. von Gaertner, Suppl. Carp. 2: 213 (1807), p.p. as to Lambertia teretifolia]
[Embothrium auct. non J.R.Forst. & G.Forst.: H.C.Andrews, Bot. Repos. 3: t. 215 (1802), p.p., only with respect to Embothrium salignum]
[Anadenia auct. non R.Br.: J.Lindley, Sketch Veg. Swan R. 30 (1839), p.p. only with respect to Anadenia hakeoides (? = H. undulata)]
Description
Shrubs or small trees with 2-armed hairs. Young growth glabrous or hairy; hairs persistent or quickly glabrescent.
Leaves sessile, sometimes cupped about stem, or with attenuate base resembling petiole, simple or compound, flat or terete, longitudinally grooved or not, toothed or entire; both surfaces similar; venation conspicuous or obscure.
Inflorescence developing within a cone of involucral bracts or not, usually axillary, rarely from older wood or terminal, few-flowered umbelliform racemes on short rachis, sometimes many-flowered on elongated rachis. Flowers pedicellate, usually paired, straight or curved in bud. Tepals splitting to base or remaining fused and splitting adaxially only. Hypogynous gland semicircular or a curved flap, rarely absent. Pistil glabrous; ovary stipitate or subsessile, 2-ovulate; pollen presenter erect, oblique or lateral, discoid or conical with narrow or broad basal flange.
Fruit a modified follicle, variously woody, often beaked, sometimes horned, usually tardily dehiscent; valves splitting fully or partly down one or both sides. Seed occupying whole valve or marginal, collateral, flattened on one side, with a distal to encircling wing clasped between valves.
Distribution and ecology
A genus of c. 150 species, all endemic to
Derivation of name
Named for Baron Christian Ludwig von Hake (1745–1818), a German patron of science and a Councillor in
The genus Conchium which was described some 6 months after Hakea by J.E.Smith was derived from the Greek word for a bivalve shell and "was given in allusion to the peculiar form of the fruit, to which it strikingly applies" (Smith 1808).
Relationships
Formerly treated in publications such as Johnson & Briggs (1975) as Tribe Grevilleeae, together with Grevillea and Finschia, the latter of 3 species predominantly from New Guinea.
More recently, following molecular studies of the whole family, Weston & Barker (2006) have proposed a revised infrageneric classification in which Hakea resides in Tribe Embothrieae Subtribe Hakeinae together with Grevillea and Finschia, but with the addition of two NE Australian genera Buckinghamia and Opisthiolepis.
Relationships of, and within, Hakea are the subject of ongoing molecular studies in the laboratory of Dr Austin Mast of
Notes
Hakea and Grevillea distinctions
Without fruits many Hakea and Grevillea species are easily confused, especially in their flowers with four tepals, an erect or recurved limb in bud, and a similar range of leaf and pollen presenter shapes. Usually they can be distinguished readily by their fruits, generally woody and persistent in Hakea as opposed to non-woody and non-persistent in Grevillea. Other useful distinguishing characters include the leaf symmetry, the ovary and the style. In Hakea the upper and lower leaf surfaces usually appear very similar both superficially and in their epidermis (termed isobilateral); in Grevillea the upper and lower surfaces usually differ (termed dorsiventral). The style and ovary of Hakea species are glabrous except in H. arborescens and H. persiehana where there are some short erect hairs on the style and in H. horrida and H. ilicifolia where there are papillae, possibly glandular, on the ovary. Styles and ovaries may be glabrous in Grevillea as well, but many Grevillea species possess hairs in these parts. Some Grevillea species develop distinct swellings or structures on the style, a characteristic unknown in Hakea. The length of the stipe supporting the ovary is also useful. The ovaries of all Hakea species, except the corkwoods, are sessile or only shortly stipitate. In the great majority of Grevillea species the ovary is stipitate; in those species which are sessile, the ovaries are densely hairy.
Other differences are documented in the introductory chapter to Grevillea in volume 17A of the Flora of Australia.
Infrageneric classification of Hakea
A history of the infrageneric classification of Hakea can be found in the introductory chapter to Hakea in volume 17B of the Flora of Australia. Within the taxonomic treatment of Hakea in that same volume the genus was split into a number of informal groups of apparently related species on the basis of some of the more obvious shared morphologies. Many of these groupings were already shown not to be supported by the generation of a preliminary cladogram based on morphology for some two thirds of the known species, but the groupings were used for convenience in presenting the taxonomy.
Refining of the relationships within Hakea are the subject of ongoing molecular studies in the laboratory of Dr Austin Mast of
Weblinks
There are a considerable number of weblinks to images and information about Hakea within each of the species fact sheets and in the introduction to the key.
Unfortunately weblinks can sometimes be transitory and apologies are made for those links which are found to be no longer functional.