Sate 
19, Sheaths pubescent. (Also, culms and 
spikelets usually so). 
20. Spikelets not more than 2 mm. long. 
21. Ligule 1-1.5 mm. long. Expected 
(P. tsugetorum). 
21. Ligule 2-5 mm. long. 
22. Axis of panicle glabrous or puberulent. 
(Also, spikelets 1.3-1.6 
mm. long). Expected (P. meridionale). 
22. Axis of panicle pilose. 
23. Spikelets 1-1.3 mm. long. 
Expected (P. leucothrix). 
23. Spikelets 1.6-1.9 mm. long. 
24. Culms, sheaths, and blades 
velvety.ccscccceecececeeee P. Lanuginosum 
24. Culms, sheaths, and blades 
spreading-pilose. Expected 
(P. huachucae). 
20. Spikelets about 2.5 mm. long. (Also, 
culms, sheaths, and blades densely 
villous). Expected (P. villosissimum). See Appendix 1. 
18. Ligule absent. 
25. Nodes bearded. 
26. Spikelets 1.3-1.5 mm. long............ P. microcarpon 
26. Spikelets 2 mm. long or more. 
Expected (P. mattamuskeetense). 
25. Nodes not bearded. 
27. Plant velvet-pubescent throughout. 
Expected (P. scoparium). 
27. Plant not velvety throughout. 
28. Sheaths pilose or hispid. 
