Stems profusely branched proximally to distally, 9--45 cm ´ 0.3--1 mm; internodes 0.3--5.2 cm, without prickes abaxially. Leaves ascending with age, 0.5--2.6 cm, stiff in age; sheath 0.7--2.8 mm wide, apex rounded; blade 0.2--1.3 mm wide, margins conspicuously serrulate, teeth 8--22 per side, apex acute, with 1 tooth, teeth multicellular; midvein without prickles abaxially. Flowers 1--2 per axil, staminate and pistillate on same plant. Staminate flowers in distal axils, 1.2--1.9 mm; involucral beaks 2-lobed, 0.3--0.5 mm; anther 4-loculed,1 mm. Pistillate flowers in proximal axils, 2 mm; styles to 0.7 mm; stigmas 4-lobed. Seeds not recurved, whitish, fusiform, 0.7--1.5 ´ 0.3--0.5 mm, apex with style situated at center; testa dull, 3 cell layers thick, pitted; aeroleareoles regularly arranged in 20 longitudinal rows, not ladderlike, 4--5-angled, longer than broad, end walls raised. Chromosome number unknown not available.

Flowering late spring--fall. Slow moving streams and ponds; 0--100 m; introduced; Fla.; Mexico; Central America (Guatemala, Belize, Honduras); West Indies (Cuba).

other referencess Davenport, L. J. 1980. In: A. Löve, ed. IOPB Cchromosome number reports. LXVII. Taxon 29: 351347--367. Les, D. H. and R. R. Haynes. 1995. Systematics of subclass Alismatidae: A synthesis of approaches. In: P. J. Rudall et al., eds. 1995. Monocotyledons: Systematics and Evolution. 2 vols. Kew. Vol. 2, pp. 353--377 47--367.