Herbs, annual or biennial [perennial]. Taproots slender. Stems decumbent to ascending, branched, terete. Leaves alternate or rarely subopposite, sometimes forming basal rosette, not connate, petiolate or sessile; stipules 2 per node, white, ovate, margins mostly entire, apex acuminate; petiole minute (subopposite leaves); blade 1-veined, narrowly oblanceolate to spatulate, not succulent, apex obtuse. Inflorescences terminal or axillary, dense cymes; bracts paired, smaller, scarious. Pedicels erect. Flowers: perianth and androecium slightly perigynous; hypanthium cup-shaped, not abruptly expanded distally; sepals 5, distinct, green or reddish brown, 1–1.5 mm, herbaceous, margins white-scarious, apex blunt, not hooded, not awned; nectaries not apparent; stamens 5; filaments distinct; staminodes 5, arising from hypanthium rim, ovate to oblong; styles 3, distinct, capitate, 0.1–0.2 mm, glabrous proximally; stigmas 3, capitate, obscurely papillate (at 50×). Utricles at least partly enclosed by persistent calyx/hypanthium, obscurely 3-gonous, indehiscent. Seeds white with tan band, reniform or subglobose, not compressed, finely papillose, marginal wing absent, appendage absent; embryo peripheral, curved. x = 8, 9.
South America, Eurasia, Africa, introduced elsewhere.
Species ca. 10 (1 in the flora).