Common Name

Dillons’ Wattle, Wilgie Mia Wattle

Family

Fabaceae

Distribution

Occurs in the midwest region of the SW arid zone in W.A. where it is known from only the Weld Ra, c. 60 km NW of Cue.

Description

Intricately branched shrub (0.3–) 0.5–1.8 m tall. Branches glabrous, dividing into numerous, short, straight, rigid, divaricate, coarsely pungent branchlets. Phyllodes crowded, normally single at nodes but often appearing sub-fasciculate on short shoots, elliptic, oblong-elliptic, obovate or oblanceolate, (5–) 7–12 (–15) mm long, (2–) 3–5 (–7) mm wide, apices asymmetrically narrowed to a slender, pungent cusp, glabrous; midrib ±prominent, lateral nerves anastomosing near phyllode margins; pulvinus distinct and 0.5–1 mm long; gland basal. Inflorescences simple; peduncles 8–20 mm long, glabrous; heads globular to obloid, yellow. Flowers 5-merous; sepals united. Pods narrowly oblong, 25–55 mm long, 4.5–5.5 mm wide, curved (sometimes into an open circle), coriaceous, reddish brown, very obscurely reticulately nerved, glabrous. Seeds longitudinal, obloid but noticeably constricted at the hilar end, 3.5–4 mm long; aril extending 1/3–1/2 down one side of the seed.

Phenology

Flowers Aug.; mature pods late Oct.

Habitat

Grows in red clay-loam or red-brown silty clay-loam on the middle and upper slopes and crests of low ranges mostly associated with outcropping basalt, in tall open shrubland.

Notes

Most closely allied to A. kochii which differs most obviously in having innocuous phyllodes, moniliform to sub-moniliform pods that are larger and larger, elliptic seeds that are not noticeably constricted at the hilar end and which possess a terminal, conical aril.

Conservation

Acacia dilloniorum is listed as Priority One under Department of Parks and Wildlife Conservation Codes for Western Australian Flora.

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