Common Name

Clay Wattle, Flat Wattle

Family

Fabaceae

Distribution

Occurs from near Narrogin S to near Manypeaks (c. 35 km due NE of Albany) and E to Israelite Bay (c. 180 km due E of Ravensthorpe), southern W.A.

Description

Prostrate or erect shrub to 1.5 m high; branches often somewhat gangling. Branchlets straight to slightly flexuose, glabrous. Stipules persistent or caducous. Phyllodes continuous with branchlets, bifariously decurrent and forming opposite wings with each one extending to the next below, usually 2.5–7 cm long and 0.6–2 cm wide, occasionally undulate, coriaceous, glaucous, glabrous except axils densely tomentulose; free portion of phyllode usually 1–4 cm long, acute to shortly acuminate, with main nerve evident; gland not prominent. Inflorescences rudimentary 1-headed racemes, with axes to 0.5 mm long; peduncles 3–18 mm long, glabrous, often patent or descending in fruit; heads globular, 5–6 mm diam., 30–80-flowered, golden. Flowers 5-merous; sepals ±free; petals nerveless. Pods somewhat irregularly coiled and twisted, subterete to compressed, to 2 cm long, 2–3 mm wide, thinly crustaceous, black, glabrous. Seeds longitudinal, ±oblong, 2.5–3.5 mm long; aril terminal, ±conical.

Habitat

Grows in clay and gravelly soils in woodland, tall shrubland and mallee communities.

Specimens

W.A.: Swan R., J.Drummond no. 1 (BM, CGE, G, FI, OXF, P, TCD); between Hamersley R. and East Mt Barren, B.R.Maslin 810 (MEL, PERTH); 17 km W of Israelite Bay Telegraph Stn towards Mt Ragged, R.A.Saffrey 1356 (CANB, K, PERTH); c. 5 km NE of Ravensthorpe towards Esperance, M.D.Tindale 3805 (BRI n.v., CANB n.v., K n.v., L n.v., MEL n.v., NSW, PERTH, US n.v.).

Notes

Most specimens from the western extremity of the range have slightly smaller than normal phyllodes, i.e. 1.5–3 cm long, 3–6 mm wide, the free portion 5–15 mm long and normally acute but sometimes rounded as in A. bifaria, e.g. 9.7 km SE of Broomehill, K.Newbey 3586 (CANB, K, MEL, NY, PERTH).

Closely related to A. bifaria and vegetatively resembling A. pterocaulon. Inflorescence and carpological characters indicate relationships with A. excentrica and the A. merrallii group even though these species do not have bifariously winged branches.

A seemingly rare variant with very undulate phyllodes occurs N of Bremer Bay (Bremer Bay is c. 65 km SE of Jerramungup), e.g. road between Bremer Bay Rd and Gairdner R., S.Paust 653 (PERTH).

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