Acanthocarpus rupestris A.S.George

Stems to 50 cm long; branches divaricate. Leaves of branches: lamina divaricate, 7-25 mm long, slender, pungent, dark green; margins finely scabrid; nerves 5, flattened; grooves almost closed, scabrid; auricles triangular to ovate, 1 mm long, lacerating; primary-stem leaves not seen. Flowers terminal; pedicels 1-1.5 mm long. Sepals and petals 3-3.5 mm long, white. Stamens 1-1.5 mm long. Pistil 1.5-2 mm long; ovary tapering to ±stout style. Capsule 4-4.5 mm long, verrucose; tubercles irregularly conical, obtuse, to 0.4 mm long. Seed 2.5 mm diam., somewhat rugose.

Grows in red sand with limestone, in Triodia-shrub steppe, sometimes by creek-lines.