Erect to prostrate shrubs; stems mostly pubescent. Leaves opposite, alternate or in whorls of 3 or 4; simple, entire, apex of pungent, margins flat, involute or slightly recurved, sessile or petiolate, venetation generally prominently reticulate; stipules usually present. Inflorescence axillary or terminal, racemose or reduced to single flowers; flowers sessile or shortly pedicellate; bracts generally caducous, occasionally persistent, nearly always scale-like, rarely leaf-like; bracteoles absent. Calyx 5-toothed, teeth usually subequal, imbricate, upper 2 usually united higher than the lower 3; petals clawed, usually yellow or orange, sometimes red, cream pale green or almost black; standard usually broader than long, emarginate, occasionally entire or acute; wings auriculate on the margin; keel lightly to strongly united, base auriculate, saccate; stamens free to base, anthers generally uniform, sometimes differing in size and shape; ovary sessile or stipitate, style incurved to hooked, stigma terminal, capitate; ovules 2–20. Pod more or less ovoid, hairy; seeds reniform to ellipsoid, arillate.
A genus of 109 species, all native to south-western Australia, except for two species which occur in northern and central Australia. Only a few species are cultivated, undoubtedly because of their reputation as poisonous plants. Many species contain monofluoroacetic acid (the sodium salt of which is also known as the commercial poison, Compound 1080) (Chandler et al. 2002) which is considered to be very toxic to stock and humans.
