192 REPORT OF NEW JERSEY STATE MUSEUM. 



U. Spikelets not over i mm. long. 

 P. wrightianum, p. 201 

 kk. Spikelets more than 1.5 mm. long. 

 /. Spikelets not over 2 mm. long. 

 m. Plant grayish, velvety pubes- 

 cent. P. lanuginosum, p. 204 

 mm. Plant pubescent, but not vel- 

 vety. 

 M. Upper surface of blade 

 glabrous. 



P. tennesseense, p. 203 

 nn. Upper surface of blade 

 pubescent. 

 o. Spikelets 1.3-1.5 mm. 

 long, blade long, pi- 

 lose above. 



P. meridionale, p. 203 



00. Spikelets 1.6-2 mm. 



long, blade appressed, 



pubescent above. 



P. huachuccB, p. 203 



II. Spikelets 2.2 mm. or more. 



m. Pubescence on culm horizon- 

 tal, spreading. 



P. villosissimum, p. 204 

 m,m. Pubescence on culms ap- 

 pressed. 



P. pseudopuhescens, p. 205 

 hh. Ligule obsolete or less than i mm. long. 

 i. Nodes bearded. 



;'. Spikelets 1.S-1.6 mm. long. 



P. microcarpon, p. 200 

 ;'/. Spikelets 2.2 or more. P. clutei, p. 201" 

 ii. Nodes not bearded. 



P. mattamuskeetense, p. 201 

 /. Plants densely gray velvety throughout, 

 a viscid ring below the nodes. 



P. scoparium, p. 209 

 //. Plants not gray velvety. 



k. Some sheaths pilose or hispid. 

 I. Pubescence papillose hispid. 

 m. Spikelets 2.3-2.6, pointed. 



P. scabriusculum, p. 210 

 mm. Spikelets obovate, obtuse, 3 

 mm. long. 



P. clandestinum, p. 211 

 II. Pubescence ascending pilose. 

 m. Spikelets 2-2.5 nm*. long. 

 ». Spikelets 2.4 mm. long. 

 P. commonsianum, p. 205 



