Plants terrestrial, annual. Stems erect, reddish brown in age, unbranched or branched, to 16 cm. Leaf blades ovate to oblong, 4-5 mm, apex with awn or mucro. Inflorescences compact; flowers 2 per node. Pedicels 1.5+ mm. Flowers 5-merous; sepals lanceolate, 1.5 mm, apex mucronate; petals lanceolate, 1.2 mm. Follicles erect or slightly recurved, 1-2-seeded, oblong-lanceoloid; old follicles ascending, boat-shaped. Seeds ellipsoid, 0.3-0.5 × 0.1-0.2 mm, not papillate, shiny, smooth.

Flowering spring. Sandy to loamy soils in open woodlands; 100-200 m; introduced; Calif.; Australia.

Subspecies lamprosperma was found along the San Gabriel River in southern California, possibly brought in as a seed contaminant at a nearby quarry (S. Boyd 2004).