GRAMINEAE 17 



sylvania : Dei^aware ; Chester ; Lancaster ; York ; Lebanon ; 

 Franklin ; Northampton ; Philadelphia ; Montgomery. 



8. SYNTHERISMA Walt. 



Xachisof the racemes merely angled : first scale wanting or rarely rudimentary. 



I. S. filiforme. 

 Rachis of the racemes with the lateral angles winged. 



Foliage glabrous : spikelets usually of 3 scales. 2. 5'. humifusutn. 



Foliage pubescent : spikelets of 4 scales. 3. S. sanguinale. 



1. Syntherisma filiforme (L.) Nash. Slender Finger-grass. 

 (Man. p. 76 ; I. V. f. 242.) In dry or sandy soil, Mass. to Mich., N. C. 

 and I. Terr. — Pennsylvania : Delaware ; Chester ; Bucks ; Lancas- 

 ter ; Philadelphia ; Crawford. 



2. Syntherisma humifusum (Pars.) Rydb. Spreading Paspalum. 

 In fields and waste places, Ont. to Kans., Fla. and La. — Pennsylvania: 

 Lancaster ; Delaware ; Chester ; Bucks ; Luzerne ; Northamp- 

 ton ; Erie ; Franklin ; Philadelphia ; Alleghen\-. 



3. Syntherisma sanguinale (L. ) Dulac. Large Crab-grass. Fin- 

 ger-grass. (Man. p. 77 ; I. F./. 240.) In cultivated ground and waste 

 places, nearly throughout N. A. Nat. from Eu. — Pennsylvania : Dela- 

 ware ; Chester ; Bucks ; Northampton ; Lancaster ; Franklin ; 

 Philadelphia ; Dauphin ; Huntingdon ; Erie ; Allegheny. Com- 

 mon. 



9. ECHINOCLOA. 



Leaf -sheaths glabrous. i. £. Crus-galli. 



Leaf-sheaths, at least the lower ones, papillose-hispid. 2. E. JValieri. 



1. Echinocloa Crus-galli (L. ) Beauv. Barny.\rd Grass. (Man. p. 

 78 ; I. F.y. 24J.) In cultivated and waste places, throughout N. A. ex- 

 cept the extreme north. Nat. from Eu. Pennsylvattia : Delaware ; 

 Chester ; Bucks ; Lancaster ; Franklin ; Northampton ; Jeffer- 

 son ; Allegheny. 



2. Echinocloa "Walteri (Pursh) Nash. SaltmarshCockspurGr.\ss. 

 (Man. p. 78; 1. F.y". 24^.) In marshes, principally near salt water, Ont. 

 to R. I., Fla. and La. — Pennsylvania : Philadelphia. 



10. PANICUM L. 



Spikelets tuberculate, the tubercles not hair-bearing. i. P. verrucosum. 

 Spikelets not tuberculate, or if so the tubercles bearing hairs. 

 A. Basal and stem leaves similar, elongated : spikelets lanceolate to ovate, 

 commonly the former, acute to acuminate, 

 a. Lower leaf-sheaths terete or but little flattened, not keeled. 

 '•■Stems finally branched, plants without long rootstocks or stolons. 

 Sheaths very pubescent. 

 Spikelets lanceolate, 3 mm. long or less. 

 Stems stout : panicle usually included at the base, its many 

 branches repeatedly divided and bearing numerous spikelets. 



2. P. capillar e. 

 Stems slender : panicle exserted, its few branches but little divided 

 and bearing comparatively few spikelets. 

 Spikelets 2 mm. long, acute. 



