TLITCHCOCK AND CHASE—TROPICAL NORTH AMERICAN PANICUM. 507 
DISTRIBUTION. 
Wet savannas and margins of ponds and streams, Costa Rica and the West Indies to 
Paraguay. The type specimen from tropical America. 
Costa Rica: Buenos Aires, Tonduz 3631, 3659, Pittier 10594. 
Cusa: Los Almacigos, Wright 3458. Uerradura, Baker 2078, Tracy 9060, 
9079, Hitchcock 181, Britton, 
Earle & Gager 6494, Pinar 
del Rio, Britton & Gager 
7075. Guane, Shafer 10659. 
Laguna Los Indios, Shafer 
10803. 
Porto Rico: Lake Loisa, Chase 
6786. Campo Alegre, Chase 
6615, 6788. Aguada, Sintenis 
5719. Guainabo, Chase 6630. 
Catafio, Sintenis 5719. Mar- Fi. 92.—Distribution of P. parvifolium. 
tin Pefia, Chase 6358. Trujillo 
Alto, Chase 6763. Vega Baja, Chase 6796, Heller 1316. 
Triniwap: Cumuto Station, Hitchcock 10065, Amer. Gr. Nat. Herb. 72. Pitch 
Lake, Hitchcock 10100. Arima, Broadway 2372. Without locality, Crueger, 
224. 
70. Panicum cyanescens Nees. 
Panicum cyanescens Nees, Agrost. Bras. 220. 1829. “‘ Habitat in Brasilia meridionali 
(Sellow).” The type is in the Berlin Herbarium. 
Panicum firmifolium Trin.; Nees, loc. cit. A herbarium name giver. as a synonym 
of P. cyanescens. 
DESCRIPTION. 
Plants perennial, bluish or glaucous; culms tufted, erect or with a decumbent base 
rooting at the nodes, slender, smooth, leafy, 30 to 50 cm. high, branching from the mid- 
dle and upper nodes; sheathsstriate, glabrous, rarely ciliate on the overlapping margin; 
ligule minute, membranaceous, sparsely ciliate with long hairs or sometimes naked; 
blades flat, rather firm, erect, spreading or reflexed, 3 to 8 cm. long, 4 to 5 mm. wide, 
oblong-lanceolate, slightly narrowed to the base, acute, 
glabrous; panicles short-exserted, terminal and often from 
the upper sheaths, 3 to 6 cm. long, as wide or wider, open, 
the slender flexuous branches rather remote, stiffly ascend- 
ing or spreading, naked below, branching and _ spikelet- 
bearing toward the ends, the spikelets on slender divaricate 
pedicels; spikelets about 1.5 mm. long, 0.9 mm. wide, turgid 
or subglobose, obtuse, glabrous; first glume two-thirds to 
three-fourthsas long as the spikelet; second glume and sterile 
lemma equal, covering the fruit, or at maturity the glume wrinkled because of the 
turgidity of the fruit, exposing the summit; fruit 1.2 mm. long, 0.8 mm. wide, very 
turgid, subacute, the lemma and palea cellular-roughened as seen under a lens, 
bearing a few very obscure appressed hairs toward the summit. 
This species resembles P. parvifolium, but differs in the less slender, more erect 
culms, longer blades, and stiffly ascending panicle branches, naked below. 
Fia. 93.—P. cyanescens. 
From type specimen. 
