GKAMINEAE (GRASS FAMILY) 



101 



65. P. Ravenelii. 



72. P.Boscii. 



73. P. latifolium. 



66. P. fcanthophytsum. 



66. P. xanthophysum. 



67. P. Wilcoxiamtm. 



59. P. mutaMle. 

 70. P. aculeatum. 



65. P. Ravenelii. 



63. P. Scribnerianum. 

 62. P. oligosanthea. 



P. strigosum. 

 P. microcarpon. 



P. lancearium. 



k. Leaves oblong-lanceolate to ovate-lanceolate, more than 5 mm. 



wide, or if narrower not conspicuously elongated I. 

 I, Blades more than 1.5 cm. wide m. 



m. Spikelets 3 mm. long ; at least the lower sheaths papillose-hispid 71. P. eland estinum. 

 m. Spikelets 3.5-4 mm. long. 



Nodes bearded ; plants often pubescent. 

 Blades lanceolate, thick, glabrous above, densely papillose- 

 pubescent beneath 



Blades ovate-lanceolate, thin ; pubescence when present 



soft 



Nodes not bearded ; plants glabrous or nearly so. 

 Panicle spreading; blades 2. 5 cm. or more wide 

 Panicle narrow ; blades rarely over 1.8 cm. wide 

 I. Blades not over 1.5 cm. wide n. 

 n. Panicle narrow ; blades erect. 



Plants glabrous or nearly so ....... 



Plants papillose-hispid. 



Spikelets not over 3mm. long 



Spikelets 4 mm. long 64. P. Leibergii. 



n. Panicle spreading, about as wide as long o. 

 o. Spikelets 3 mm. long; blades 1.2-2 dm. long. 



Blades ciliate, glaucous, smooth 



Blades not ciliate, green, scabrous 



o. Spikelets 3.5-4 mm. long ; blades not over 1 dm. long. 



Nodes bearded ; ligule 3-4 mm. long 



Nodes not bearded ; ligule 1-2 mm. long. 

 Spikelets obo void-turgid, blunt ; pubescence spread- 

 ing 



Spikelets narrowly obovoid, subacute ; pubescence 



appressed 



y. Spikelets less than 3 mm. long p. ^ 



p. Spikelets glabrous q. 



q. Spikelets not over 1.5 mm. long. 



Plants pubescent 



Plants glabrous, except bearded nodes 



q. Spikelets 2-2.5 mm. long r. 

 r. Spikelets 2 mm. long. 



Spikelets obovoid-turgid; culms crisp-puberulent 

 Spikelets elliptical ; culms glabrous. 



Autumnal state erect, branched like a little tree; second 



glume shorter than the fruit and sterile lemma . 

 Autumnal state topheavy-reclining ; fruit covered by 



second glume and sterile lemma 



Autumnal state widely trailing; second glume and 



sterile lemma shorter than the fruit .... 

 r. Spikelets 2.5 mm. long. 



Culms 2-4 dm. high ; second glume and sterile lemma 



equaling fruit 



Culms 5-12 dm. high ; second glume and sterile lemma 



forming a point beyond the fruit 



p. Spikelets pubescent n. 



8. Blades elongated, not over 5 mm. wide ; secondary panicles 

 from the base only, or none. 



Sheaths glabrous 20. P. Werneri. 



Sheaths pilose. 

 Spikelets turgid, blunt ; panicle-branches ascending ; 



culms few in a tuft 18. P. perlongum. 



Spikelets subacute ; panicle-branches spreading ; culms 



numerous in a tuft 19. P. linearifolium. 



s. Blades iisually not conspicuously elongated ; secondary 



panicles not at the base t. 

 t. Spikelets obovate-turgid, blunt, attenuate at base. 



Spikelets 2 mm. long 25. P. aciculare. 



Spikelets 2.5 mm. long. 



Spikelets not papillose ; culms glabrous . . . . 26. P. Bicknellii. 

 Spikelets rugose-papillose ; culms pubescent, at least below. 

 Nodes bearded ; panicle-branches ascending . . . 24. P. consanguineum. 

 Nodes not bearded ; panicle-branches spreading . 

 t. Spikelets not attenuate at base u. 



u. Sheaths conspicuously retrorse-pilose ; culms simple, form- 

 ing soft tufts 



u. Sheaths not retrorsely pilose . 

 . Sheaths, or all but the lowest, glabrous w. 

 to. Ligule 2-5 mm. long. 



Spikelets 2.2 mm. long 



Spikelets 1.5 mm. long. 



Panicle not more than half as wide as long; 



spikelets elliptic 

 Panicle about as wk 



27. P. dichotomum. 



28. P. barbulatum. 



). P. lucidum. 



26. P. Bicknellii. 

 29. P. yadkinense. 



23. P. angustifolium . 



21. P. xalapense. 



47. P. tcoparioides. 



fide as long ; spikelets obovoid 



35. 

 36. 



P. spretum. 

 P. Lit 



idheimeri. 



