Plant: Annual, short-lived perennial herb, glabrous; stem decumbent to erect, 1-5 cm Leaves: opposite, ± 4-ranked; blades oblong, ± entire, tips rounded tapered to base; petiole ± 1/2 X blade, flat, ± blade-like INFLORESCENCE: flowers 1 per node Flowers: sepals 4, fused in basal ± 1/3, separating in fruit, membranous, very pale green; petals 4, > and wider than sepals; stamens 8; filaments ± 1/2 X to ± = petals, anthers widely ovoid; styles 3-4 Fruit: Fruit: capsule, ± spheric or depressed-ovoid; chambers 4, each 3-15- seeded; pedicel recurved, 2-3 X fruit; Seed ± visible through fruit wall, oblong to elliptic, curved 90-180 degrees; pits ± 15 per row, as wide as or wider than long, brown to yellowish brown; surface net-like Misc: Pools, ponds, rice fields, streambanks; 50-1900 m.