Common Name

Two-flowered Acacia

Family

Fabaceae

Distribution

Occurs from the Stirling Ra. Natl Park–Albany area E to near Jerramungup and Bremer Bay with disjunct occurrences in the Scaddan area and at Lucky Bay, south-western W.A.

Description

Shrub 0.3–0.6 m high. Branchlets sparsely to densely puberulous to shortly pilose. Phyllodes inequilateral, obtriangular to obdeltate with a prominent gland-bearing angle on adaxial margin, with adaxial proximal margin ±contiguous with branchlet, 3–7 mm long and 3–8 mm wide, may reach 15 mm long and wide on old stems, pungent, glabrous or hairy; midrib near abaxial margin, with a minor nerve extending from base towards the gland. Inflorescences simple, 1 per axil; peduncles 3–8 mm long, glabrous to sparsely hairy; heads globular, 2-flowered, white to cream; buds abruptly acute. Flowers 4-merous; sepals c. 3/4-united, with broadly triangular lobes; petals glabrous, ±obscurely 3–7-nerved at apices. Pods narrowly oblong, curved, to 5.5 cm long, 4–5 mm wide, coriaceous-crustaceous, glabrous; margins thick. Seeds longitudinal, ±oblong, 3–3.5 mm long, glossy, greyish brown; aril terminal.

Habitat

Usually grows in sand in woodland, low mallee scrub or shrubland.

Specimens

W.A.: Swan R., J.Drummond (?4:) 2 (BM, G, G-DC, K, MEL, OXF, P, PERTH, W); 19.5 km S of Grass Patch towards Esperance, B.R.Maslin 2507 (PERTH); 16 km S of Jerramungup towards Albany, B.R.Maslin 2589 (CANB, K, PERTH); 2 km W of Lake Carabundup, A.E.Orchard 4391 (PERTH).

Notes

Acacia biflora, together with A. chrysocephala, A. divergens, A. incrassata, A. mooreana, A. phlebopetala and A. robinae comprise the ‘A. biflora group’, fide B.R.Maslin, Nuytsia 2: 270 (1978). These species are similar vegetatively but readily distinguished by inflorescence and flower characters. Acacia biflora is recognised by a combination of the following features: heads white to cream and 2-flowered, peduncles 3–8 mm long, petals 2–3.5 mm long and 3–7-nerved at apices. The species with which A. biflora is most likely to be confused are A. chrysocephala and A. robinae. Specimens from the Fitzgerald R. Natl Park combine phyllodes of A. biflora with flowers of A. robinae.

FOA Reference

Data derived from Flora of Australia Volumes 11A (2001), 11B (2001) and 12 (1998), products of ABRS, ©Commonwealth of Australia

Author

B.R.Maslin