GRASS FAMILY 171 



Panicle open, the branches spreading. 

 Awn short or wanting. 



Lemmas broad, oblu.se 7. B. hrizaeformis. 



Lemmas acuminate 18. B. unioloides. 



Awn well-developed (cf. B. earinatus). 



Awn twisted and bent 1. B. trinii. 



Awn not twisted and bent. 



Sheaths smooth; florets turgid; awn 1% to 214 lines long 2. B. secaliiius. 



Sheaths pubescent; awn usiiall.v long. 



Awn 11,4 to 2 inches long 10. B. villnsus. 



Awn not more than 8 lines long. 



First glume 1-nerved 12. B. tcrtorum. 



First glume 3-nerved. 



Lemmas pubescent 6. B. arenarius. 



Lemmas glabrous. 



Awns all alike 3. B. commuiatus. 



Awns of the low<'r florets shorter 5. B. japonirus. 



Plants perennial. 



Spilielets subterete, not strongly flattened. 



Panicle narrow, the liranehes erect 17. B. snlsdorfii. 



Panicle open, the branches spreading. 



Branches of panicle stiffly divaricate; blades short 13. B. orcutiinmix. 



Branches drooping; blades elongated. 



Lemmas pubescent throughout 14. B. grandis. 



Lemmas pubescent at margins or base only, or nearly glabrous. 



Lemmas densely pubescent at base and margins; lower glume 3-nerved 



Ifi. B. laevipes. 

 Lemmas sparsely pubescent on back, ciliate on margins or nearly glabrous; lower 



glume 1-nerved 15. B. vulgaris. 



Spikelets strongly flattened. 



Blades canescent and densely pilose, narrow or involute ]9. B. suhvelutiiius. 



Blades not canescent, glabrous or somewhat pilose, broader, flat. 



Panicle narrow, the branches short and erect 21. B. maritimus. 



Panicle open, the branches spreading or drooping. 



Awn less than S^o lines long; blades rather broad 20. B. marr/inatus. 



Awn more than Slj, lines long; blades usually narrow 22. B. carinahts. 



Division I. Introduced annuals (cf. B. unioloides in Div. 3). 



1. B. trinii Desv. Culms erect. 1 to 2 feet high; sheaths pilose or nearly 

 smooth ; bhulcs usually pilose ; panicle narrow, 4 to 8 inches long, rather dense ; 

 spikelets narrow, 5 to 7-tiowered. 7 to 10 lines long; glumes lanceolate, acu- 

 minate, smooth, the first mostly 1-nerved, 4 to 5 lines long, the second broader, 

 mostly 3-nerved, 6 to 8 lines long; lemmas coarsely and sparsely pubescent, 

 5-nerved, 6 to 7 lines long, acuminate, with 2 narrow teeth 1 line long; awn 

 7 to 10 lines long, twisted below, bent below tlie middle and strongly divaricate 

 when old. 



Dry plains and rocky or wooded slopes: Klamath Bluffs, Siskiyou Co. {Butler 

 1185) ; San Francisco and Contra ('osta cos. south, especially in desert regions; 

 east to Coldcado and south to Jlesieo; also Chile. 



Var. excelsus Shear. Lemma 7-nervcd, the awn scarcely twisted or bent. — 

 A little known form which may prove to be a distinct species. The type is from 

 the Panamint I\Its. {Cnville & Funston 522). Another specimen, Wilder 1062, 

 from Glenavon, is doubtfully referred to this variety. 



Rets.— Bromus trinu Desv. iii Gay, Fl. Chil. 6: 441. 185.3; Abrams, Fl. Los Ang. 53. 1904. 

 Var. pallidiflorus Desv. in Gay, Fl. Chil. 6: 441. 1853; Abrams, Fl. Los Ang. 54. 1904. Trise- 

 tum barbatum Steud. Syn. PI. Glum. 1: 229. 1854; Davy in Jepson, Fl. W. Mid. Cal. 52. 1901. 

 Var. EXCELSUS Shear, U. S. Dept. Agr. Div. Agrost. Bull. 23: 25. 1900. 



