MANUAL OF THE GRASSES OF THE WEST INDIES 245 
Blades linear, often elongate; glumes not carinate or but slightly so. 
Fruit transversely rugose. 
INedestbesrded. 22 anni tains eles Ty 2. P. PURPURASCENS. 
INN CSPO ta CACC Oe te es ee 1. P. GEMINATUM. 
Fruit not rugose. 
Spikelets not expanded at maturity by an enlarged sterile palea, 
FLOR GCE GE Sete shes Corse eve eeres Beh eto 32. P. POLYGONATUM. 
Spikelets expanded at maturity by the enlarged sterile palea. 
Blades narrowed toward the base__-_____-__-- 36. P. LAXUM. 
Blades cordate or truncate at base. 
pues 2 mm long; panicle branches erect or nearly 
Si sell os Pe me LON rs tei dates orc nts 37. P. STEVENSIANUM. 
Spikelets not more than 1.6 mm long; panicle branches 
spreading or ascending. 
Panicles one-third to half as wide as long; spikelets not 
conspicuously secund, somewhat irregularly dis- 
posed; blades cordate-clasping__35. P. BOLIVIENSE. 
Panicles rarely one-fourth as wide as long; spikelets 
conspicuously secund and regularly disposed. 
Culms as much as 2 m long; panicles 25 to 30 cm 
NOW Se ae aR eel lyase = 33. P. MILLEFLORUM. 
Culms not more than 1 m tall; panicles 5 to 15 cm 
LCN aN Cay ees te Sp a Leek PY Gigi a eas Ri 34. P. PILOSUM. 
6b. Spikelets in open or sometimes in contracted or congested panicles, 
but not in 1-sided spikelike racemes. 
ISGWELSERANSMEESChY; TUR OSCa = 19 1 (2 ane BL Wy El oe 8 19. P. MAXIMUM. 
Fruit not transversely rugose. 
Culms more or less succulent. Plants glabrous or nearly so through- 
out, aquatic or subaquatic. 
First glume not more than one-fifth the length of the spikelet. 
Spikelets 4 to 5 mm long; fruit long-acuminate____________---- 
12. P. ELEPHANTIPES. 
Spikelets 2 to 3 mm long; fruit not acuminate. 
Spikelets: 2 mmrlong 24 2s Vie pe k 10. P. LACUSTRE. 
Spikelets about 3 mm long_____________-_ 11. P. aquaTicum. 
First glume one-third to one-half the length of the spikelet. 
Culms erect, panicle contracted__________- 31. P. cONDENSUM. 
Culms long- decumbent at base; panicle open___54. P. GRANDE. 
Culms not succulent. 
First glume not more than one-fifth the length of the spikelet or 
wanting (occasionally a long glume developed in P. discrepans.) 
Fruit felty villous at base and apex; first glume often minute or 
wanting; fruit keeled, pubescent at apex_57. P. DISCREPANS. 
Fruit not felty villous; first glume evident; fruit not keeled, 
sparsely pubescent all over__________-_ 42. P. SCHIFFNERI. 
First glume more than one-fifth the length of the spikelet. 
Sterile palea enlarged and indurate at maturity, expanding the 
Bpikeletrrisumes Jey MANgla es 38. P. EXIGUIFLORUM. 
Sterile palea, if present, not enlarged and indurate. 
First glume less than one-third the length of the spikelet, 
Ro ainnetja fo = sae pt fh bed aN a ee oe 9. P. BARTOWENSE. 
First glume usually more than one-third the length of the 
spikelet. 
7a. Plants forming conspicuous hard creeping rhizomes. 
First glume less than half the length of the spikelet; 
spikelets not more than 2.5 mm long. 
Panicle loosely flowered; first glume truncate, about one- 
fifth the length of the spikelet____20. P. REPENS. 
Panicles rather densely flowered; first glume triangular,. 
about one-third the length of the spikelet____---_- 
21. P. GOuUINI. 
First glume more than half the length of the spikelet; 
spikelets 3 to 4 mm long. 
Culms decumbent or creeping at base, mostly 2 to 4 
m tall 23. P. ALTUM- 
