 Photo © B.Norris |
 Photo © B.Norris |
 Photo © B.Norris |
 Photo © B.Norris |
Synonymy
Hakea bicornata R.M.Barker, J. Adelaide Bot. Gard. 13: 104 (1990)
T: 10.5 km NW of Clyde Hill, 37 km ENE of Mt Heywood, W.A., 26 May 1990, W.Archer 2605901; holo: AD; duplicates to be distributed.
Description
Multi-stemmed, much-branched shrub, 1–1.3 m tall, lignotuberous. Branchlets appressed-pubescent, ferruginous. Leaves simple, 7–13 cm long, 1.2–1.5 mm wide, appressed-sericeous, ferruginous, quickly glabrescent; mucro 1.5–2.5 mm long.
Inflorescence axillary with 8 flowers; involucre 1–1.5 mm long; rachis obscure; pedicels 3.5–4.5 mm long, glabrous; buds curved. Perianth c. 2.5 mm long, cream-white, glabrous. Pistil 4.0–4.5 mm long; pollen presenter oblique, ±conical.
Fruit obliquely broadly elliptic or obovate, 1.5–2.2 cm long, 1.2–1.5 cm wide, black-pusticulate on pale grey bark, not beaked, obscurely apiculate; horns 5–6 mm long, very narrow. Seed obovate, 11 mm long, 5.5 mm wide; wing broadly down one side of seed-body only, black or dark brown.
Distribution and ecology
Rarely collected species from Cape Arid Natl Park through to the Esperance area, W.A.
Occurs on lateritic clay or clay loam over granite in shrubland.
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 have been recorded in Mar., May and Aug.
Derivation of name
Epithet is from bi-, Latin for two, and cornu, Latin for horn, a reference to the two prominent horns on the fruit. In making this epithet, it should have more correctly been spelled as 'bicornuta', but the original spelling stands.
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.
H. bicornata is part of the Strumosa group, a group close to the Sericea and Nodosa groups and held together by the sharing of simple terete leaves, terminal or axillary inflorescences (if the latter these resprouting in subsequent seasons), glabrous pedicel and perianth and woody, smooth or verrucose, fruits with horns.
Other species in the group include H. circumalata, H. commutata, H. cycloptera, H. newbeyana, H. preissii, H. strumosa and H. vittata.
Conservation status
This species was treated as 'Poorly Known' in J.D.Briggs & J.H.Leigh, Rare or Threatened Australian Plants (1995), but is no longer included on the list of Western Australia's Declared Rare and Priority Flora List.
Representative specimens
W.A.: c. 30 km SSW of Mt Ragged, A.S.George 2079 (
Weblinks
Link to FloraBase treatment of this species for WA.
Further illustrations
J.A..Young, Hakeas of Western Australia. A Field and Identification Guide 16 (2006)