32 FLORA OF PHILADELPHIA. 



5. SORGHASTRUM Nash. 



1. Sorghastrum avenaceum (Michx.) Nash. Indian Grass. M. p. 71. 

 Dry fields. Late summer. 



6. PASPALUM L. 



Raehis of the racemes very broad, twice the width of the spikelets, or nearly 

 so, which are partially concealed by its inrolled margins. 



1. P. membranaceum. 

 Raehis of the racemes narrower than the spikelets, not inrolled on the 

 margins. 

 Racemes 2, approximately in a pair at the summit of the culm; root- 

 stocks extensively creeping; culms not tufted. 2. P. distichum. 

 Racemes 1 to several, alternate, eulms tufted. 



Culms simple, no branches from the upper sheaths; racemes stout. 

 Spikelets 3 mm. long or less. 3. P. laeve. 



Spikelets 4 mm. long or more. 4. P. glabratum. 



-nil. Culms branched, the upper sheath containing from 1-3 branches; 



racemes slender. 

 Culm densely pilose below the racemes; lower sheaths usually 



glabrous or nearly so. 5. P. pubescens. 



Culm glabrous ; lower sheaths generally hirsute. 



Spikelets 1-1.5 mm. long. 6. P. setaeewm. 



Spikelets 2-2.25 mm. long. 7. P. Muhlenbergii. 



1. Paspalum membranaceum Walt. M. p. 73. - Low or wet ground. Sum- 



mer. , 



Gloucester— Mickleton (C). Salem— Penn Grove (C), Riddleton (Li.). 

 Cape May— Cape May '(C). Atlantic— Landisville (C). 

 New Castle— Col. Andrews. 



2. Paspalum distichum L. M. p. 73. Wet fields. Summer. 



Camden— Kaighn's Point, I. Burk (Fu.). 



3. Paspalum laeve Michx. M. p. 73. Moist soil. Summer. 



4. Paspalum glabratum (Bngelm.) Mohr. M. p. 73. Moist soil. Summer. 



Cape May— Cape May (Li.) (TJ. C S.), Anglesea, Dr. J. B. Brinton 

 (He.). 



5. Paspalum pubescens Muhl. M. p. 74. In fields. Summer. 



Montgomery — Willow Grove (P.). Delaware— Tinicum. Crura Cjfeek. 

 (St.). Chester- W. Bradford Twp. (St.). &/f^vW / p'W, fiwi\ 



6. Paspalum setaceum Michx. M. p. 74. Dry fields. Summer. ^ 



7. Paspalum Muhlenbergii Nash. M. p. 75. Sandy or stony ground. 



Summer. 

 Philadelphia— (P.). Bucks— Penn "Valley (Fr.). Delaware— Tinicum 

 (P.). Chester— (P.). Lancaster— (P.). Northampton— (P.). 



7. AMPHICARPON Raf. 



1. Amphicarpon Amphicarpon (Pursh.) Nash. M. p. 76. Moist pine bar- 

 rens. Summer. 



8. SYNTHERISMA Walt. 



Rachis of the racemes with the angles wingless; first scale of the spikelet 

 wanting, or sometimes present as an inconspicuous rudiment. 



1. S. filiformis. 



