Mayaca fluviatilis Aubl.

Herbs, submerged or terrestrial. Stems sometimes much branched and matted, decumbent to erect, to 60 cm, usually much less. Leaves: blade narrowly lanceolate to linear, 2--20(--30) cm  0.5 mm, apex entire or 2-fid. Flowers to 1 cm wide; pedicels 2--12 mm, elongating in fruit to 20 mm; sepals persistent, ovate to lanceolate-elliptic, 2--4.5 ´ 0.7--1.5 mm; petals rose to maroon or lilac, sometimes whitish basally, broadly ovate, 3.5--5 ´ 3--4.5 mm; stamens 1.5--3 mm; filaments 1--2 mm; anthers 0.5--1 mm, dehiscing by means of apical, porelike slits; pistils 2--2.3 mm, stigmas 3-lobed to 3-fid. Capsules nearly globose to ellipsoid, often irregular because of abortion, to 4 ´ 3.4 mm. Seeds 2--25 per capsule, nearly globose, to 1.3 ´ 0.9 mm; seed coat scrobiculate or ridged and pitted.