242 MISC. PUBLICATION 243, U.S. DEPT. OF AGRICULTURE 
Robust branching perennial growing in tough clumps; culms 1 to 
2 m long, often decumbent or creeping at base; blades flat, 15 to 30 
em long, 8 to 15 mm wide; panicle subflabellate, feathery; racemes 
numerous, slender, silky, drooping, 15 to 30 em long, the axis short; 
spikelets 2.5 to 3 mm long, lanceolate, acuminate, bearing a fringe 
of pale silky hairs as much as 5 to 8 mm long (fig. 196). 
Open brushy or jungly slopes, mostly in moist spots, Costa Rica 
and the Lesser Antilles to Bolivia. 
LEEWARD IsLANDs: St. Kitts, Bor 151. Dominica, Imray 311. 
WINDWARD IsuAnps: Martinique, Duss 1317. Grenada, Broad- 
way 62, 2919, and in 1905; Smith 192, 843. 
TRINIDAD: Cedros, Hitchcock 10134. Without locality, Broadway 
in 1919. 
Tosaao: Adelphi, Broadway 3979. Center of island, Hitchcock 
10278. 
80. PANICUM L., Sp. Pl. 55. 1753 
Spikelets more or less compressed dorsiventrally, arranged in open 
or compact panicles, rarely in racemes; glumes herbaceous, nerved, 
usually very unequal, the first often minute, the second typically 
equaling the sterile lemma, the latter of the same texture and simu- 
lating a third glume, bearing in its axil a membranaceous or hyaline 
palea and sometimes a staminate flower, the palea rarely wanting; 
fertile lemma chartaceous-indurate, typically obtuse, the nerves 
obsolete, the margins inrolled over an enclosed palea of the same text- 
ure. Annuals or perennials of various habit. 
la. Axis of branchlets produced beyond the base of the uppermost spikelet as a 
point or bristle 1 to 6 mm long, sometimes nearly obsolete. Culms cespitose, 
a slender rhizome developed in some species, usually found in P. leonis, often 
in P. utowanaeum, but rarely in the others (Subgenus PAUROCHAETIUM). 
Second glume about as long as fruit, this and the sterile lemma faintly retic- 
ulate; first glume rounded or truneate_-_-=___-- = _2 89. P. CHAPMANI. 
Second glume about two-thirds as long as fruit, neither this nor the sterile 
lemma reticulate; first glume usually acute. 
Panicles strict, 15 to 35 cm long; spikelets spreading.._._92. P. PRADANUM. 
Panicles not strict, mostly subflexuous, not more than 10 cm long; spikelets 
not spreading (a few sometimes slightly spreading). 
Blades 4 to 7 mm wide, thickish, mostly flat, 5 to 15 em long. 
94. P. LEONIS. 
Blades 1 to 3 mm wide, flat to involute. 
Spikeletsale4: toy 125 mamyl ong es eee ee 91. P. DISTANTIFLORUM. 
Spikelets 1.8 to 2.5 mm long. 
Blades flat or folded toward the apex, mostly 3 to 8 cm (rarely to 12 
ae) long, the basal crowded in a tuft, those of the culm spread- 
DT U8 GA ERY AE Je et eee SE 90. P. OPHITICOLA. 
Blades of the innovations involute, 8 to 20 em long, ascending, the 
basalinotinvardensestuit sess 93. P. UTOWANAEUM. 
1b. Axis of branchlets not produced into a bristle. (In P. geminatum the some- 
what flattened axis pointed but not bristle-form.) 
2a. Basal leaves usually distinctly different from those of the culm, forming 
a winter rosette; culms at first simple, the spikelets of the primary panicle 
not perfecting seed, later usually becoming much branched, the small 
secondary panicles with cleistogamous fruitful spikelets (Subgenus 
DICHANTHELIUM). 
Foliage soft and lax, the flat blades prominently ciliate; plants branching 
from the base, finally forming rosettes or cushions (Laaiflora). 
Spikelets papillose-pilose; sheaths retrorsely pilose___59. P. XALAPENSE. 
Spikelets glabrous; sheaths not retrorsely pilose. 
Blades slabrous:onsphe SUbLaACe = 45 aeete: eee ere 60. P. POLYCAULON. 
Biladesspiloseron, Gheysuriace 55 see meee ee 61. P. sTRIGOSUM. 
