Sketch Bot. S. Carolina 1: 370. 1817.
Herbs, winter annual, often hemispheric tufts. Stems erect, branched or unbranched. Leaves basal and cauline, alternate or subopposite; stipules absent; petiole present; blade margins entire; venation palmate. Inflorescences terminal, cymules or flowers solitary. Flowers bisexual, radially symmetric or weakly asymmetric; perianth and androecium perigynous; hypanthium completely adnate to ovary; sepals 5, connate proximally; petals 0 or (4–)5, white, 0–0.4 mm, much shorter than sepals; nectary absent; stamens 5; staminodes 5, opposite petals, undivided, not gland-tipped; pistil 3-carpellate; ovary inferior, 1-locular, placentation parietal; styles 3, weakly connate proximally; stigmas 3; ovules 40–70. Fruits capsules, 1-locular, 3-valved, obpyramidal, apex not beaked. Seeds 40–70 per fruit, oblong, not winged; aril absent. x = 23.
sc, se United States, Mexico, South America (Chile, Uruguay).