HITCHCOCK AND CHASE—GRASSES OF THE WEST INDIES. 323 
Spikelets pubescent. 
Spikelets attenuate at base, mostly prominently pustulose; blades nar- 
row, stiff, strongly nerved, tapering from base to apex. (ANGUSTI- 
FOLIA. ) 
Nodes bearded; plants grayish-villous; autumnal blades flat, rather 
soft _--_-----------------_---------- 54. P. chrysopsidifolium. 
Nodes not bearded; plants villous only at base, or nearly glabrous; 
autumnal blades involute. 
Spikelets 3 to 3.5 mm. long, pointed__------__-_-_ 55. P. fusiforme. 
Spikelets less than 3 mm. long, not pointed or obscurely so, 
Plants glabrous or nearly so; autumnal culms erect; spikelets 
subsecund along the subereet panicle branches, 
57. P. neuranthum. 
Plants pubescent, at least on the lower half. 
Spikelets not over 2 mm, long; vernal blades 4 to 6 cm. long; 
autumnal blades much crowded, falcate__53. P. aciculare. 
Spikelets 2.2 to 2.4 mm. long; vernal blades 7 to 12 cm. long; 
autumnal blades not falcate______-__ 56. P. arenicoloides. 
Spikelets not attenuate at base, not pustulose; blades lanceolate to 
linear-lanceolate but usually less than 10 times as long as broad. 
Sheaths glabrous. 
Spikelets subglobose or pyriform. 
Blades erect, 7 to 13 cm. long, 7 to 14 mm. wide; spikelets 
spheroid _.__---_-___-__-_____--_----- 65. P. erectifolium. 
Blades spreading, rarely over 5 cm. long and 5 mm. wide; 
spikelets pyriform; autumnal form bushy-branching. (Lan- 
CEARIA.) 
Spikelets 1.5 to 1.6 mm. long__-_-___-__-_-_ 68. P. portoricense. 
Spikelets 2 mm. long_ - _69. P. lancearium. 
Spikelets elliptic to obovate. 
Nodes glabrous. 
Spikelets 2.8 to 3 mm. long; blades commonly 1 cm. wide, not 
white-margined _-.____________________-__- 72. P. joorii. 
Spikelets not over 1.5 mm. long; blades not over 6 mm. wide, 
with a cartilaginous white margin. 
66. P. albomarginatum. 
Nodes bearded ; blades not white-margined ; spikelets 2 mm. long. 
Sheaths, at least the upper, viscid-spotted; autumnal phase 
erect or reclining _______________________ 58. P. nitidum. 
Sheaths not viscid-spotted; autumnal phase decumbent, with 
flabellate-fascicled branches_______~ 59. P. multirameum. 
Sheaths pubescent. 
Culms usually 75 cm. or more tall; foliage velvety-pubescent. 
Vernal culms erect or ascending; plants velvety throughout; 
spikelets about 2.5 mm. long_____________ 70. P. scoparium., 
Vernal culms decumbent at base; upper sheaths more or less 
glabrate; spikelets less than 2 mm. long__71. P. viscidellum., 
Culms not over 50 cm. tall. 
Plants conspicuously villous throughout____64. P. acuminatum. 
Plants appressed-pubescent on the culms and sheaths; blades 
glabrous above. 
Spikelets 1.2 to 1.3 mm. long_----..---____- 62. P. leucothrix. 
Spikelets not over 1 mm. long.___....._~ 63. P. wrightianum. 
