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-gr.^ss, 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; Cafion 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. pubcsccns 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 Caiion, Las Animas Co.; 

 Boulder. 



10. ECHINOCHLOA Beauv. Barnyard-grass, Cockspur-grass. 



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

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

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



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

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



II. 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. 



