 Inflorescences and leaves; flat, simple terete and compound terete leaves are present. Photo © W.R.Barker |
 Inflorescences; note the very diagnostic lateral pollen presenter and the flat leaves. Photo © W.R.Barker |
 Inflorescences; note the erect fruit, similar to flattened leaves in other images. Photo © W.R.Barker |
 Inflorescence, flat and terete leaves and open fruit (bottom LHS), lacking any wood. Photo © W.R.Barker |
Synonymy
Hakea trifurcata (Sm.) R.Br., Trans. Linn. Soc. London 10: 183 (1810)
Conchium trifurcatum Sm., in A.Rees Cycl. 9 (1807), pages unnumbered; Trans. Linn. Soc. London 9: 122 (1808). T: King George Sound, [Western Australia], 1803, A.Menzies s.n.; holo: LINN; iso: BM, K p.p.
Hakea trifurcata var. eriantha Meisn., in J.G.C.Lehmann, Pl. Preiss. 1: 558 (1845), nom. illeg. (H. trifurcata in synonymy).
Hakea trifurcata var. sericantha Meisn., in J.G.C.Lehmann, Pl. Preiss. 1: 559 (1845). T: Guildford, Western Australia, 14 Sept. 1839, L.Preiss 591; syn: G-DC, LD p.p., LE, ?NY.
Hakea mixta Lindl., Sketch Veg. Swan R. xxxvi (1840). T: Swan R. district, Western Australia, without date, J.Drummond s.n.; syn: BM p.p., CGE, CGE p.p., G, K p.p.
Hakea tricruris Lindl., Sketch Veg. Swan R. xxxvi (1840). T: south-western Western Australia, without date, J.Drummond s.n.; holo: CGE.
Hakea boucheana Kunth, Pl. Nov. Hort. Berol. 9 (1844); Linnaea 18: 499 (1844). T: Hort. Berol., Apr. 1843, Anon. s.n.; ?holo: B.
Description
Dense or open shrub, 0.4–2.5 m tall, to 2 m diam., non-lignotuberous. Branchlets appressed-pubescent or appressed-sericeous, ferruginous. Leaves terete and/or flat, appressed-sericeous, with hairs ferruginous and white, quickly glabrescent; flat leaves elliptic or obovate, 2–5 cm long, 6–19 mm wide, attenuate or cuneate, entire, rounded apically; terete leaves simple or compound, 2.2–7.5 cm long, 0.8–1.3 mm wide, grooved on lower side.
Inflorescence with up to 10 flowers; involucre 4.5–5.5 mm long; pedicels 3–4 mm long, tomentose or appressed-sericeous, with hairs cream or ferruginous, extending onto perianth. Perianth 6.5–8.5 mm long. Pistil 8.5–10 mm long; pollen presenter 0.9–1.1 mm long; gland c. 0.3 mm high.
Fruit leaf-like, obliquely obovate, 1.5–2.3 cm long, 0.5–0.8 cm wide, smooth, not beaked. Seed narrowly obovate, 13 mm long; wing apical only.
Distribution and ecology
Common throughout the south-western corner of Western Australia south from Murchison R. to east of Cape Arid. Found in sand or laterite in low open heath or mallee.
To plot an up to date distribution map based on herbarium collections for this species see Australia's Virtual Herbarium. Localities outside the native range may represent cultivated or naturalised records.
Flowering time
Flowers Apr.–Oct.; a form with white or pale styles may flower in the earlier part of this range.
Derivation of name
From tri-, Latin or Greek for three-, and furca, Latin for forked - a reference to just one of the leaf forms of this species.
Relationships
Part of Section Hakea of Bentham (as Euhakea) and characterised by a non-conical pollen presenter, leaves without obvious venation, perianths with or without hairs and fruits with or without horns. Barker et al. (1999) recognised a number of informal morphological groups within the section.
The Trifurcata group all share the characteristics of compound-terete leaves, pubescent pedicel and perianth, lateral pollen presenter and non-woody, non-horned, camouflaged fruits which are not retained for any length of time on the bushes.
Members of the group are H. erinacea, H. lasiantha, H. lasianthoides, H. longiflora and H. trifurcata, all from SW WA. The monophyly or otherwise of the group has still to be tested.
Notes
Flowers of H. trifurcata possess a strong smell, sometimes described as fetid, and bees and blowflies have been seen visiting them. The fruit are cryptic and closely resemble the flat leaves which are only produced once the plants reach sexual maturity.
H. trifurcata varies with respect to hair covering on the perianth and pedicel. Specimens from Dryandra, York, Lake King, Kulin and Tutanning Nature Reserve, equivalent to Meisner's var. sericantha, have a mixture of ferruginous and white appressed-sericeous hairs on the pedicel and perianth. Specimens with white hairs on both pedicel and perianth, or with ferruginous hairs on the pedicel contrasting with the white or brown hairs of the perianth, occur north of Perth. Populations with pale brown hairs, either tomentose on pedicel and perianth or more usually tomentose on the limb and appressed on the claw, occur throughout the range of distribution of the species.
There are a number of PERTH collections with pale styles compared with the more normal red style, e.g. R.Hnatiuk 770273, A.S.George 6317, E.Scrymgeour 870, M.Carter 203. These are found in the more arid and more easterly localities and usually have mainly pale brownish tomentose hairs on the whole perianth.
Since flat leaves are rarely present in younger plants it is postulated that the flat leaves do not form on this species until fruits are formed and that they serve as camouflage to protect the "leaf-like" fruits.
Representative specimens
Western Australia: between Katanning and Kojonup, W.E.Blackall 3127 (PERTH); Cape Le Grand National Park, between Rossiter Bay car park and the Bird Sanctuary, M.Carter 203 (PERTH); 20 km E of Geraldton road on road to Calingiri, G.J.Keighery 1349 (PERTH); Yorkrakine Rock Reserve, 24 km N of Tammin, B.G.Muir 449(3.7) (PERTH); Strawberry Hill, Irwin R. area, F.G.Smith 1703 (PERTH).
Weblinks
Link to FloraBase treatment of this species for WA.
More photographs of this species can be seen on the Australian National Botanic Gardens site.
Further illustrations
I. Holliday, Hakeas. A Field and Garden Guide 206-7 (2005)
J.A..Young, Hakeas of Western Australia. A Field and Identification Guide 113 (2006).