Panicum aquaticum Poir.

Panicum aquaticum Poir. in Lam. Encyc. SuppL 4: 281. 1816
Panicum chloroticum sylvestre Nees; Trin. Gram. Pan. 236. 1826. Panicum hygrophilum Salzm.; Steud. Syn. Gram. 71. 1854. Panicum proliferum strictum Griseb. Cat. PL Cub. 232. 1866.
Plants perennial, mostly aquatic, glabrous except as noted; culms usually decumbent at base, rooting at the nodes, erect branches often arising therefrom, the flowering culms erect, simple or sparingly branching, averaging lower and more slender than in P. dichotomiflorum; leaf -sheaths usually overlapping, rarely pilose at the juncture with the blade; ligule a ring of hairs about 1 mm. long; blades commonly elongate, as much as 25 cm. long, but sometimes 5-10 cm. long and abruptly pointed, 5-10 mm. wide, linear, acute, occasionally sparsely pilose on the upper surface toward the base; panicles terminal and axillary, short-exserted or included at base, averaging smaller than those of P. dichotomiflorum, rarely as much as 20 cm. long, less freely branching and fewer-flowered, the branchlets and pedicels smooth or nearly so on the angles; spikelets 3-3.4 mm. long, 1 mm. wide, more gradually pointed than those of P. dichotomiflorum, the fruit slightly larger and more pointed than in that species.
Typb locality: Porto Rico.
Distribution: Cuba, Porto Rico, and Guadeloupe; Colima; Guatemala; also in tropical