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291 



branches, the lower in distant fas- 

 cicles, have been differentiated as T. 

 projection Louis-Marie. Intergrading 

 specimens are more numerous than 

 the extreme described. 



Figure 391. — Trisetum canescens. Panicle, X 1; 

 glumes and floret, X 5. (Hitchcock 3409, Calif.) 



Figure 392. — Trisetum montanum. Panicle, X 1; 

 glumes and floret, X 5. (Type.) 



7. Trisetum montanum Vasey. 

 (Fig. 392.) Resembling T. canescens, 

 on the average smaller, the blades 

 narrower; sheaths from nearly gla- 

 brous to softly retrorsely pubescent; 

 panicles smaller than usual in T. 

 canescens, more uniformly rather 

 dense, often purple-tinged; spikelets 

 5 to 6 mm. long, the glumes and 

 lemmas thinner than in T. canescens, 

 the awn more delicate, 5 to 8 mm. 

 long. % — Mountain meadows, 

 gulches and moist places on moun- 

 tain slopes, between 2,000 and 3,300 



m., Colorado, Utah, New Mexico, 

 and Arizona. A form with purplish 

 panicles and erect awns only 2 to 3 

 mm. long, known from a single 

 collection near Silverton, Colo., has 

 been differentiated as T. montanum 

 var. shearii Louis-Marie. 



8. Trisetum flavescens (L.) Beauv. 

 (Fig. 393.) Resembling T. canescens; 

 sheaths glabrous or the lower sparsely 

 pilose ; panicle usually yellowish, many- 

 flowered, somewhat condensed ; spike- 

 lets mostly 3- or 4-flowered; lemmas 

 4 to 6 mm. long. % — Waste 

 places, Vermont, New York, Missouri, 

 Colorado, Washington, California, 

 and probably other States; intro- 

 duced from Europe. 



Trisetum aureum (Ten.) Ten. An- 

 nual; culms 10 to 20 cm. tall; panicle 

 ovate, contracted, 2 to 3 cm. long; 

 spikelets 3 mm. long; awns 2 to 3 

 mm. long. —Ballast, Camden, 

 N. J.; Europe. 



9. Trisetum pennsylvanicum (L.) 

 Beauv. ex Roem. and Schult. (Fig. 

 394.) Culms slender, weak, usually 

 subgeniculate at base, 50 to 100 cm. 

 tall; sheaths glabrous or rarely sca- 

 brous; blades flat, scabrous, 2 to 5 

 mm. wide; panicle narrow, loose, 

 nodding, 10 to 20 cm. long; pedicels 

 disarticulating about the middle or 

 toward the base; spikelets 5 to 7 mm. 



Figure 393. 



-Trisetum flavescens. Panicle, X 1; floret, 

 X 5. (Grant 26, Wash.) 



