Plants terrestrial, perennial. Stems erect, green, moderately branched, 30-50 cm. Leaf blades linear to triangular, 10-30 mm, apex mucronate. Inflorescences lax, flowers 2 per node. Pedicels 3-5 mm. Flowers 5-merous; sepals (erect), triangular, 1 mm, apex acute; petals narrowly triangular, 2-3 mm. Follicles erect, 6-10-seeded, ovoid; old follicles erect, boat-shaped. Seeds not seen. Flowering Mar-Jun. Disturbed sites; 0-400 m; introduced; Calif.; Africa (South Africa). Crassula tetragona is naturalized in southern California.