Plant: Annual, short-lived perennial herb, glabrous; stem prostrate to erect, 3-6(15) cm, often tinted reddish Leaves: opposite, ± 4-ranked; oblong-lanceolate; petiole < 1/4 blade, flat, ± blade-like; tip blunt to notched INFLORESCENCE: flowers 1-2 per node Flowers: sepals 2 or, if 3, 1 < others, membranous, very pale green; petals 3, equal, widely elliptic, membranous, pale greenish white; stamens 3, opposite sepals, filaments ± 1/2 X to ± = petals, anthers widely ovoid; styles 3-4 Fruit: Fruit: capsule, ± spheric or depressed-ovoid; chambers 3; each 3-15- seeded; pedicel generally ± 0; Seed narrowly oblong, straight or curved < 15 degrees; pits 16-35 per row, ± as wide as long Misc: Muddy shores, shallow vernal pools, ditches, rice fields; < 500 m.