Plants short-lived. Stems 3-6 dm; internodes 1-5 cm; often rooting at nodes. Leaf blades 1-3 × 0.5-5 cm, minutely papillate, appearing smooth. Inflorescences solitary flowers; axillary pedicel 8-15 mm. Flowers: hypanthium 6-7 mm; calyx lobes 2-5 mm; petals 80, reflexed, pink to purple (red in hybrid cultivar 'Red Apple'), 3-4 mm; staminodia 50, erect, white, 3 mm. Capsules 13-15 mm. 2n = 18.

Flowering spring-fall. Disturbed places, coastal bluffs, margins of coastal wetlands, 0-100 m; introduced; Calif., Oreg.; Europe (British Isles); Africa; Australia.

The flowers of Aptenia cordifolia open during the bright hours of the day.