POACEAE. 21 



1. Syntherisma humifusum (Pers.) Rydb. On roadsides, in old fields and 

 waste places, introduced from the Old World and established from N. S. to 

 Mont, and Colo, and Fla. Alt. 4000-9000 ft. Georgetown; Ft. Collins. 



2. Syntherisma sanguinale (L.) Dulac. (Panicum sanguinale L.) In 

 lawns, cultivated ground and waste places ; introduced from 'the Old World 

 and established from Mass, to Neb., Fla. and Calif. Alt. about 5000 ft 

 Boulder; Canon City; Ft. Collins. 



8. TRICHACHNE Nees. 



i. Trichachne saccharatum (Buckley) Nash. On dry hillsides from Colo, to 

 western Tex., Ariz, and Mex. Alt. up to 8500 ft. Canon City; Fremont Co. 



9. PANICUM L. PANIC-GRASS, WITCH-GRASS, SWITCH-GRASS, MILLET. 



Basal leaf-blades long and narrow ; spikelets lanceolate to ovate, acute to acu- 

 minate. 



Annual. i. P. capillare. 



Perennial with long, scaly root-stock. 2. P. virgatum. 



Basal leaf-blades ovate to lanceolate ; spikelets elliptic to ovate or obovate, obtuse. 



Spikelets less than 2 mm. long. 3. P. unciphyllum. 



Spikelets more than 2 mm. long. 4. P. Scribnerianum. 



1. Panicum capillare L. In sandy soil and waste places from S. Dak. to 

 B. C, N. M. and Calif. Alt. 4000-9500 ft Black Canon; Ft. Collins; Pike's 

 Peak; Grand Junction; near Boulder; Canon City; Colorado Springs; 

 Graymont. 



2. Panicum virgatum L. In meadows and on river-banks from Me. to Ass., 

 Fla. and Ariz. Alt. 4000-7500 ft Ft Collins; Golden; Trimble Springs; 

 New Windsor, Weld Co.; near Boulder; La Veta; Tobe Miller's ranch. 



3. Panicum unciphyllum Trin. (P. pubescens and P. dichotomum of Coult. 

 Man.) In dry or sandy soil from Me. to B. C, Ga. and Ariz. Exact local- 

 ity not given. 



4. Panicum Scribnerianum Nash. (P. scoparium of Coult. Man.; not 

 Lam.) In meadows from Me. to B. C., Va., Ariz, and Ore. Alt. 4000-6000 

 ft. Foot-hills, Larimer Co.; Palmer Lake; Brantly Canon, Las Animas Co.; 

 Boulder. 



10. ECHINOCHLOA Beauv. BARNYARD-GRASS, COCKSPUR-GRASS. 



i. Echinochloa Crus-galli (L.) Beauv. (Panicum Crus-galli L.) In sandy 

 or alkaline soil, waste places and old fields. Alt 4000-5500 ft. Golden; 

 Grand Junction ; Dry Creek, Larimer Co. ; Canon City. 



Echinochloa Crus-galli mutica is a variety with short awn. Golden; Tobe 

 Miller's ranch, near La Porte; Ft Collins. 



n. CHAETOCHLOA Scribn. FOX-TAIL GRASS, ITALIAN MILLET, HUNGARIAN 



GRASS. 



Inflorescence with the spikelets racemosely arranged; bristles 5-16 at the base 



of each spikelet, involucrate, tawny-orange. i. C. glauca. 



Inflorescence with the spikelets in clusters or on branches ; bristles 1-3 at the 

 base of each spikelet, not involucrate. 



