Common Name

Motherumbung

Family

Fabaceae

Distribution

Sporadic on the western slopes and plains of N.S.W. from Dubbo to Gilgandra and Bourke, and in southern and central Qld from near Westmar, E to Yarranvale and N to c. 100 km N of Jericho. According to L.Pedley, Austrobaileya 2: 350 (1987), it is usually locally common.

Description

Bushy shrub or small tree to 5 (-8) m high, glabrous, somewhat resinous. Branchlets slender, somewhat angular at extremities. Phyllodes usually narrowly oblong-elliptic to oblanceolate or narrowly oblanceolate, mostly straight, 2–5 cm long, usually 3–6 mm wide, l:w = 4–14, normally obtuse with a ±thickened central mucro, thin, with sparsely tuberculate margins; midrib not prominent; lateral nerves obscure, ±subparallel to midrib; gland minute, 1–3 mm above pulvinus, with another at base of mucro. Inflorescences simple, 1 per axil; peduncles, 4–12 mm long, ebracteate at base; heads showy, fragrant, globular, 20–30-flowered, bright golden. Flowers 5-merous; sepals c. 3/4-united. Pods narrowly oblong to linear, rounded over seeds, to 6 cm long, usually 5–8 mm wide, firmly chartaceous, brown. Seeds longitudinal, oblong to elliptic or ovate, narrowed at hilar end, 3–4 mm long; funicle folded below the oblique aril.

Habitat

Grows in sand, often with Eucalyptus melanophloia and Callitris columellaris.

Specimens

Qld: 12.3 km S of Charleville on Cunnamulla road, M.E.Ballingall 2381 (PERTH); c. 80 km WSW of Springsure, 1 Dec. 1984, B.O’Keeffe (PERTH). N.S.W.: Dubbo, Dec. 1907, J.L.Boorman (NSW).

Notes

Specimens of M.S.Clemens, 8 Oct. 1945 (BRI), from Charleville are slightly unusual in having linear phyllodes 1.5–3 mm wide and pods 3–4 mm wide.

A member of the ‘A. johnsonii group’, distinguished from its closest relatives, A. eremophiloides, A. gnidium and A. hockingsii by its phyllode proportions.

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

Minor edits by J.Rogers