102 



POACEAE 



13. Echinochloa Beau v. 



Sheaths glabrous. 1 . E. Crus-galH. 



Sheaths, at least the lower ones, densely papillose-hirsute. 2. E. Walteri. 



i. E. Crus-galli (L.) Beauv. In cultivated and waste places; 

 nearly throughout N. Am. Native of Europe. 

 Common as a weed. 



2. E. Walteri (Pursh.) Nash. In marshes and ditches along the 

 coast: Ont. to R. I., Fla. and Tex. 



Common along the coasts, decreasing inland and not recorded 

 from the northern part of our range; rare in the pine-barrens. 

 E. frumentacea (Roxb.) Link has been collected as a waif. 



14. Panicum L. 



Spikelets on one side of the rachis on short pedicels forming 



1 -sided racemes. I. Paspaloidea. 



Spikelets arranged in panicles, the divisions sometimes strict 

 and narrow but not 1 -sided. 

 Basal leaf-blades long and narrow, similar to those of the 

 stem; no rosulate tufts of leaves in the fall; spike- 

 lets lanceolate to ovate, acute to acuminate ; rarely 

 obtuse. 

 Spikelets manifestly tuberculate. 

 Spikelets not tuberculate. 



Basal leaf-sheaths round or but little flattened, 

 not keeled. 

 Annuals. 



Perennial by long rootstocks or stolons. 

 Rootstocks and stolons naked or with 



a few large scales. IV. 



Rootstocks and stolons with numerous 

 small broad scales. V. 



Basal leaf-sheaths much compressed, broad, 



keeled, often equitant. VI. 



Basal leaf-blades unlike those of the culm, ovate to ovate- 

 lanceolate; perennial by rostulate tufts which form in 

 the fall at the base of the culms; spikelets elliptic to 

 spheric, usually obtuse, rarely acute, never acuminate. VII. Dichotoma. 



II. Verrucosa. 



III. Capillaria. 

 Halophila. 



VlRGATA. 



Agrostoidea. 



I. Paspaloidea 



Represented only by 



1. P. hemitomon. 



Represented only by 



II. Verrucosa 



III. Capillaria 



Spikelets lanceolate or elliptic, 3 mm. long or less. 

 Leaves glabrous. 



2. P. verrucosum. 



3. P. dichotomiflorum. 



