Family

Fabaceae

Distribution

Occurs in north-western W.A. in the vicinity of Shay Gap and Cape Keraudren N to Nalgi Stn (inland of the Eighty Mile Beach). Often common in the places where it occurs.

Description

Multi-stemmed, glabrous shrub 1–3 m high. Branchlets with crenulate resin ribs at extremities, yellow or yellow-green. Phyllodes narrowly elliptic to narrowly oblong-elliptic, with a thickened hard apical point erect, mostly ±incurved, (3.5–) 5–7 (–8.5) cm long, 3–5 mm wide; with 3–8, rather widely spaced, raised (when dry) resinous longitudinal nerves, minor nerves sometimes sparingly anastomosing; gland 0–2 mm above pulvinus. Inflorescences simple; peduncles 4–12 mm long; spikes 10–30 mm long, bright golden. Flowers 5-merous; calyx shortly dissected into broadly triangular lobes, white membranous. Pods narrowly oblanceolate, narrowed towards the base, erect, woody, opening elastically (and explosively) from the uncinate apex with the dehisced valves recurved, 5–8 cm long, 6–10 mm wide, obliquely nerved, yellow. Seeds oblique and seated in shallow yet distinct chambers, 4–5 mm long, brown; pleurogram bordered by a narrow band of dull yellow tissue; funicle-aril straight, white and narrowly turbinate.

Phenology

Flowers June–July.

Habitat

Grows in red sand or loam, on flats or low dune country in open Acacia shrubland (with species such as A. ancistrocarpa, A. hilliana, A. adoxa var. adoxa and A. sericophylla) with spinifex ground cover.

Specimens

W.A.: Nalgi Stn, Eighty Mile Beach, N.T.Burbidge 1317 (PERTH); 48.5 km E of North West Coastal Hwy on Mount Goldsworthy-Shay Gap road, B.R.Maslin 8420 (PERTH).

Notes

This entity was recognized in B.R.Maslin et al., Wattles of the Pilbara CD-ROM (2010), and is possibly intermediate (both morphologically and geographically) between W.A. representatives of A. drepanocarpa subsp. drepanocarpa and A. drepanocarpa subsp. latifolia. In W.A. subsp. drepanocarpa has long, narrow phyllodes (mostly 1–2 mm wide) and occurs on the western edge of the Great Sandy Desert (it is commonly seen along North West Coastal Hwy in the vicinity of Anna Plains and Frazier Downs stations) but it does not reach the Pilbara region. Acacia drepanocarpa subsp. latifolia is seemingly rare in the Pilbara, reaching just the north-eastern edge of the region in the vicinity of Gregory Ra. (c. 150 km SE of Shay Gap) and is most obviously distinguished from Acacia sp. Nalgi (N.T. Burbidge 1317) by its generally broader phyllodes (6–) 8–12 mm wide.

FOA Reference

Flora of Australia Project

Author

B.R.Maslin