Plant: perennial, aquatic or amphibious herb, of brackish and fresh water, generally glabrous; AERIAL STEMS mostly 20-60 (-100) cm tall Leaves: mostly 5-35 mm long, 1-3 mm wide; whorled in sets of (4-)6-12(-16), simple, estipulate; margins entire; submersed leaves slender, thin and flaccid, often soon degenerating; aerial leaves thicker and firmer, numerous and rather crowded, linear-attenuate Flowers: solitary in upper leaf axils, inconspicuous, sessile or the lower on short pedicels; perfect or rarely imperfect, occasionally polygamous; calyx reduced to an inconspicuous, 2-4-lobed or subentire rim around the top of the ovary; petals none; stamen 1, with a short, slender filament and a large 2-celled sagittate anther; pistil simple, the ovary inferior, unicarpellate; style terminal, elongate, slender, generally lying in the groove between the two anther sacs, with anthers 1 mm long, 0.5-1 mm wide, the filament about as long; style 1-2 mm long Fruit: FRUITS ellipsoid-obovoid, 1.7-2.5 mm long, 1 mm wide Misc: Rooted in mud of shallow, standing or slow-moving water, and in wet meadows; 2300-2850 m (7600-9400 ft); Jun-Jul (fr. Jul-Aug) REFERENCES: Ricketson, Jon. 1995 Hippuridaceae. J. Ariz. – Nev. Acad. Sci. 29(l): 25.