292 CONTRIBUTIONS FROM THE NATIONAL, HERBARIUM. 



25. BROMIJS L. Brome grass. 



Erect annuals or perennials, with flat blades and several to many-flowered, rela- 

 tively large spikelets, borne in open or narrow panicles. 

 Plants annual, introduced weeds. 

 Culms in low tufts; spikelets long-awned. 



Spikelets villous 1. B. tectorum. 



Spikelets glabrous or nearly so la. B. tectorum nudus. 



Culms 50 cm. or more tall; spikelets short-awned 2. B. secalinus. 



Plants perennial, native except no. 5. 



Spikelets strongly flattened, the glumes compressed -keeled. 



Lemmas glabrous or scabrous only 3. B. polyanthus. 



Lemmas pubescent 4, B. marginatus. 



Spikelets not flattened, the glumes convex. 

 Plants with creeping rootstocks. 



Lemmas glabrous, mostly awnless 6. B. inermis. 



Lemmas pubescent on the margin, short-awned 6. B. pumpellianus. 



Plants without rootstocks. 



Ligule prominent, 3 to 5 mm. long 7. B. vulgaris. 



Ligule obscure, about 1 mm. long 8. B. richardsonii. 



1. Bromus tectorum L. Belton, in waste ground. Native of Eur.; widely 

 naturalized in N. Amer. — Plants often in extensive colonies, softly pubescent, with 

 conspicuously drooping panicles of narrowly V-shaped, long-awned spikelets. 



Young plants rather handsome but becoming unsightly in age; the awned florets 

 injurious to grazing animals. 



la. Bromus tectorum nudus Klett & Richt. East entrance, on open slopes. 

 Native of Eur.; naturalized in N. Amer. — Plants less pubescent than in the species, 

 the spikelets glabrous or nearly so. 



This and the typical form are very common in the park at low altitudes, in culti- 

 vated or waste ground and on open slopes. 



2. Bromus secalinus L. Chess or cheat. Belton, in gravelly open ground. 

 Native of Eur.; widely naturalized in N. Amer., especially in grain fields. — Plants 

 glabrous; panicles nodding, mth rather heavy plump glabrous spikelets. 



3. Bromus polyanthus Scribn. At middle altitudes, in woods. Oreg. to N. Mex. 

 and Mont. — Plants tufted, leafy, commonly 1 meter or more tall, with flat lax blades 

 and narrow, rather stiff panicles; lemmas with shining yellowish margins and 

 short awns. 



4. Bromus marginatus Nees. Common at low and middle altitudes, in woods or 

 on open slopes. B. C. to Calif., Aiiz., and Alta. — Plants in small tufts, 60 to 100 cm. 

 tall, with elongate blades, 5 to 12 mm. wide, and rather stiff panicles, the purplish 

 short-awned spikelets 2. .5 to 4.5 cm. long. 



5. Bromus inermis Leyss. East entrance, on dry bank. Native of Eur.; adven- 

 tive in N. Amer. — Culms commonly 1 meter or more tall, with glabrous leaves and 

 many-flowered panicles, the numerous branches whorled and ascending, the spikelets 

 loosely flowered, rather soft, oblong, 2 to 3 cm. long. 



6. Bromus pumpellianus Scribn. At low and middle altitudes, sometimes about 

 timber line, on prairie or open slopes. Alaska to Colo, and S. Dak. — Culms 50 to 

 100 cm. tall, the leaves more or less pubescent; panicle narrow, the fascicled branches 

 often spikelet-bearing nearly to the base; spikelets 2 to 3 cm. long. 



7. Bromus vulgaris (Hook.) Shear. At low and middle altitudes, in woods or on 

 open slopes. B. C. to Calif, and Mont. — A slender, yellowish green, woodland 

 grass with softly pubescent leaves and nodding panicles, the spikelets pubescent 

 and with slender awns. 



