254 MISC. PUBLICATION 243, U.S. DEPT. OF AGRICULTURE 
open, many-flowered, 20 to 30 cm long, the branches ascending, sca- 
brous, the lower fascicled, the others solitary or in pairs, the branches 
of the second order appressed along the main branches, the basal 
part of the latter naked; spikelets oblong-lanceolate, glabrous, about 
2 mm long, tinged with purple, the ultimate lateral pedicels 1 to 2 
FIGURE 205.— 
Panicum lacus- 
tre. Panicle 
lonely S< vile 
spikelet and 
NO TOt. 0 >GlG 
(type). 
mm long; first glume truncate or broadly triangular, 
one-fourth to one-third as long as the spikelet; second 
elume and sterile lemma equal, the glume 5-nerved, the 
lemma 7-nerved, without stamens or palea; fertile lemma 
smooth, slightly shorter than the spikelet, rather thin; 
anthers 1 mm long (fig. 205). 
Type in the United States National Herbarium, 
no. 1387529, collected-in water of 30 to 60 cm depth in 
Laguna de la Maquina, prov. Pinar del Rio, Cuba, 
October 31, 1923, by Dr. E. L. Ekman (no. 17878). 
Known only from the type collection, but Dr. Ekman 
states that the species occurs 1n practically all lagunas 
of the western part of Pinar del Rio Province. The 
species differs from P. dichotomiflorum in being an erect 
perennial with smaller spikelets, and from P. aquaticum 
in the erect habit and smaller spikelets. 
11. Panicum aquaticum Poir., in Lam., Encyel. Sup. 4: 
281. 1816. Puerto. Rico. 
Panicum proliferum var. strictum Griseb., Cat. PI. 
Cub. 232. 1866. Cuba, Wright 3456. 
Perennial; culms usually decumbent at base and 
rooting at the nodes, the erect flowering branches 30 to 
100 cm tall; sheaths glabrous; blades linear, 5 to 10 mm 
wide, flat or folded, usually pilose on the upper surface 
at least toward the base; panicles similar to those of 
P. dichotomiflorum but averaging smaller; spikelets 3 to 3.4 mm long, 
acuminate; fruit shorter than the spikelet, somewhat pointed (fig. 206). 
Wet places or in shallow water, margins of streams and ponds at 
low altitudes, Mexico and the West Indies to Paraguay. 
Cusa: Herradura, Hitchcock 23444; Shafer 
10912. Jovero, Léon 15367. Pinar del Rio, 
Mitchcock 23290; Wright 3861. El Sabalo, 
Léon 15097. 
part). Habana, Léon 4155. Ariguanabo 
lagoon, Léon 1975, 1976. El Cano, Léon 
1974. Guanabacoa, Léon 919. Puentes 
Grandes, Ekman 502, 18294. Motembo, 
Léon 9410. 
Marianao, Léon 5702. Isla de Pinos, Britton 
and Wilson 14803. 
Purerto Rico: Rio Piedras, Stevenson 
Almacigos, Wright 3456 (Qn 
Manacas, Léon 5823, 5998. 
3566: Chase 6778. Campo Alegre, Chase PSee tt Patan or 
Two views of spikelet, and floret, 
6804. Adjuntas, Chase 6471. Utuado, x 10 (type). 
Britton and Cowell 432. 
LEEWARD ISLANDS: Guadeloupe, Duss 3178. 
TrinipaD: Pitch Lake, Hitchcock 10099 (Amer. Gr. Nat. Herb. 
502). 
