23^ 



POACEAE 



23. Bromus trinii Desv 



Chilian Brome-t!rass. 



Fig". 55 



2 



lS5o 



Bromiis trinii 'Desv. in Gay, Fl. Chil. 6: 441. 



Bromus trinii pallidiflorus Desv. in Gay, Fl. Chil. 6: 441. 

 1853. 



Trisetum barbatum Steud. Syn. PI. Glum. 1: 229. 1854. 



Culms erect, 30-60 cm. tall ; sheaths pilose or 

 nearly smooth ; blades usually pilose ; panicle nar- 

 row, 10-20 cm. long, rather dense ; spikelets narrow, 

 5-7-flowered, 1.5-2 cm. long; glumes lanceolate, 

 acuminate, smooth, the first mostly 1-nerved, 8-10 

 mm. long, the second broader, mostly 3-nerved, 12- 

 16 mm. long ; lemmas coarsely and sparsely pubes- 

 cent, 5-nerved, 12-14 mm. long, acuminate, with 2 

 narrow teeth 2 mm. long; awn 1.5-2 cm. long, 

 twisted below, bent below the middle and strongly 

 divaricate when old. 



Dry plains and rocky or wooded slopes, in the Upper and 

 Lower Sonoran Zones; California to Colorado and Mexico; 

 Chile. Mar.-May. Type locality: Chile. 



Bromus trinii excelsus Shear, U. S. Dept. Agr. Div. 

 Agrost. Bull. 23: 25. 1900. A little known form from the 

 Panamint Mountains (Corille & Fuiistoii). It differs in 

 having larger spikelets, 7-nerved lemmas, and a scarcely 

 twisted or bent awn. 



24. Bromus secalinus L 



Chess, Cheat 



Bromus secalinus L. Sp. PI. 76. 1753. 



Fig. 553. 



Culms erect, 30-60 cm. tall ; sheaths smooth ; panicle 

 pyramidal, drooping, 7-12 cm. long, open, the lower 

 branches 3-5, unequal ; spikelets ovoid-lanceolate, be- 

 coming somewhat laterally compressed and turgid in 

 fruit; 1-2 cm. long. 6-8 mm. wide; glumes smooth, 

 obtuse, the first 3-5'nerved, 4-6 mm. long, the second 

 7-nerved, 6-7 mm. long ; lemmas 7-nerved, 6-8 mm. 

 long, elliptic, obtuse, smooth or scabrous, the margin 

 strongly involute in fruit, shortly bidentate at apex, the 

 undulate awn usually 3-5 mm. long ; palea about as long 

 as lemma. In fruit the turgid florets are somewhat 

 distant so that, viewing the spikelet sidewise, the light 

 passes through the small openings at the base of each 

 floret. 



A weed in grain fields and waste places, more or less through- 

 out the United States; introduced from Europe. June-July. Type 

 locality, European. 



25. Bromus tectorum L. 

 Downy Brome-grass. Fig. ; 



Bromus tectorum L. Sp. PI. 77. 1753. 



>4. 



Culms 30-60 cm. tall, smooth, slender; sheaths and 

 blades pubescent; panicle broad, rather dense, droop- 

 ing, 5-15 cm. long, the branches slender; spikelets 

 nodding, linear, becoming cuneiform in flower, 12-20 

 mm. long; glumes narrow, acute, villous, the first 1- 

 nerved, 4-6 mm. long, the second 3-nerved, 8-10 mm. 

 long ; lemmas lanceolate, acute, villous or pilose, 5- 

 nerved, 10-12 mm. long, bidentate at apex ; awn 

 straight, 12-14 mm. long. 



Along roadsides, banks, and waste places; introduced from 

 Europe; common on the Pacific Coast in Washington and Ore- 

 gon, occasional elsewhere. June— July. Type locality, European. 



Bromus tectorum nudus Klctl, & Richter, Fl. Leipz. 109, 

 1830. Differs in having glaljrous spikelets. Oregon and Cali- 

 fornia. 



