Plants annual. Stems mostly erect, 1-3(-5) dm. Leaves alternate or opposite; blade elliptic to narrowly lanceolate, 4.5-8 × 1-3.5 mm. Pedicels erect in fruit, 2.5-4 mm, mostly equaling or shorter than subtending leaf. Flowers: sepals (4-)5, calyx divided nearly to base, 2-2.5 mm, equaling or longer than corolla, margins entire, narrowly or not scarious, apex acuminate; petals 5, corolla white, salverform (almost rotate), 1.5-2.3 mm. Capsules 1-1.5 mm. Seeds 5-12. Flowering spring-early winter. Ditch banks, other open sites; 0-20 m; Fla.; Mexico; West Indies (Jamaica); Central America; South America (Colombia, Ecuador).