Plants annual; roots fibrous. Stems prostrate to suberect; trichomes sparse at nodes and in inflorescence, stems otherwise glabrous; branches 5-20 cm. Leaf blades obovate, spatulate, or sometimes lan-ceolate, flattened, 10-35 × 2-15 mm, apex rounded to truncate; involucrelike leaves 4-5. Flowers 8-15 mm diam.; petals yellow or yellow tipped with red or copper, spatulate or obovate, 5-10 × 3-6 mm, apex acute or cuspidate; stamens 7-30; stigmas (3-)5-18. Capsules obovoid or turbinate, 3-5 mm diam., with encircling, expanded, membranaceous wing 0.5-1.5 mm wide proximal to suture. Seeds gray, round or elongate, flattened, 0.5-1 mm; surface cells stellate with long tubercles. Portulaca umbraticola is a common weedy species of the southwestern United States, while in the southeastern United States it is usually restricted to sandy soils of granitic and sandstone outcrops. In 1982-1983, a new cultivar was introduced to the United States in hanging baskets, under the name Portulaca umbraticola `Wildfire Mixed,´ which appears to be selected from material from South America. There is no seed surface variability in any of the three subspecies.