Plants annual, fleshy; roots fibrous. Stems prostrate to sub-erect, somewhat woody toward base; trichomes sparse at nodes, sparse to moderate in inflo-rescence; branches to 25 cm. Leaf blades linear to lanceolate, terete, 6-14 × 0.5-3 mm, apex obtuse; involucrelike leaves 5-7. Flowers 20-25 mm diam.; petals connate basally, purple-red, narrowly obovate-cuneate, 10-12 × 6-9 mm, apex deeply 2-lobed; stamens 40 or more; stigmas 4-6(-7). Capsules subglobose, 2.5-5 mm diam. Seeds gray, 0.7-0.8 mm diam.; surface cells mostly stellate, tuberculate. 2n = 18. Flowering late summer-fall. Shallow soil-filled depressions, Altamaha grit sandstone outcrops; 0 m; introduced; Ga.; West Indies (Cuba). Portulaca biloba, previously known only from Cuba, is presently known from five sites in three Georgia counties. The infrequency of chasmogamous flowers suggests that it is 'out of habitat.' The earliest collection is from 1965, but the date of its first introduction to the United States is unknown. One theory of introduction suggests seeds brought in by tropical storms (J. F. Matthews et al. 1991).