Annual or perennial herbs, dwarf shrubs (in Victoria), rarely small trees, sometimes spiny, usually covered with simple or glandular hairs. Leaves alternate, pinnately trifoliolate, rarely 1-foliolate or with 2–5 pairs of leaflets (not in Victoria), petiolate; leaflets usually toothed, terminal largest; stipules conspicuous, leafy, adnate to petiole. Inflorescence axillary, flowers solitary, in 2–3-flowered clusters, or in spikes or racemes. Calyx campanulate or tubular, teeth equal; petals pink, purple, rose, yellow or white; standard orbicular, short-clawed; wings obovate-oblong; keel incurved, more or less beaked; stamens monadelphous, alternate filaments dilated at the apex, anthers alternately short and versatile, long and basifixed; ovary subsessile, ovules 2–8, style inflexed, glabrous, stigma terminal, subcapitate. Pod linear, oblong, ovate or rhombic, turgid or cylindric, sessile or subsessile, dehiscent; seeds 1–many, reniform, punctate, smooth or rugose, exarillate.
70–80 species from Europe, northern Africa and western Asia; 3 naturalised species in Australia.
Willis (1973) notes the appearance of O. natrix L. (Goat Root) at Campbells Creek near Castlemaine in 1864, but it apparently has not persisted there. It is a much-branched dwarf shrub with panicles of lame yellow flowers often with red or purple stripes.
Willis, J.H. (1973). A handbook to plants in Victoria, Melbourne University Press, Carlton.