288 



MISC. PUBLICATION 200, U. S. DEPT. OF AGRICULTURE 



Newfoundland to Vermont, Michigan, appressed, mostly 3-flowered, 8 to 9 



and Wisconsin. 



Figure 387. — Trisetum wolfii. Panicle, X 1; glumes 

 and floret, X 5. (Swallen 809, Calif.) 



2. Trisetum wolfii Vasey. Wolfs 



trisetum. (Fig. 387.) Culms erect, 

 50 to 100 cm. tall, loosely tufted, 

 sometimes with short rhizomes; 

 sheaths scabrous, rarely the lower 

 pilose; blades flat, scabrous, rarely 

 pilose on the upper surface, 2 to 4 

 mm. wide; panicle erect, rather dense 

 but scarcely spikelike, green or pale, 

 sometimes a little purplish, 8 to 15 

 cm. long; spikelets 5 to 7 mm. long, 

 2-flowered, sometimes 3-flowered; 

 glumes nearly equal, acuminate, about 

 5 mm. long; lemmas obtusish, sca- 

 berulous, 4 to 5 mm. long, awnless or 

 with a minute awn below the tip, 

 the callus hairs scant, about 0.5 mm. 

 long, the rachilla internode about 2 

 mm. long, rather sparingly long- 

 villous. % — Meadows and moist 

 ground, at medium altitudes in the 

 mountains, Montana to Washington, 

 south to New Mexico and California. 



3. Trisetum orthochaetum Hitchc. 

 (Fig. 388.) Culms solitary, erect, 

 slender, 110 cm. tall; sheaths gla- 

 brous; blades flat, scabrous, 8 to 20 

 cm. long, 3 to 7 mm. wide; panicle 

 slightly nodding, lax, pale, about 18 

 cm. long, the filiform branches loose- 

 ly ascending, Daked below, the lower 

 fascicled, as much as 8 cm. long; 

 spikelets short-pediceled, somewhat 



mm. long excluding awns, the rachilla 

 appressed-silky; glumes acuminate, 

 about 6 mm. long, the second wider; 

 lemmas rounded on the back, mi- 

 nutely scaberulous on the upper part, 

 obscurely 5-nerved, the callus short- 

 pilose, the apex acute, erose-toothed, 

 awned about 2 mm. below the tip, 

 the awn straight or nearly so, ex- 

 ceeding the lemma about 3 mm. % 

 — Known only from boggy meadows, 

 Lolo Hot Springs, Bitterroot Moun- 

 tains, Mont. 



Figure 388. — Trisetum orthochaetum. Panicle, X 1 ; 

 glumes and floret, X 5. (Type.) 



4. Trisetum cernuum Trin. Nod- 

 ding trisetum. (Fig. 389.) Culms 

 rather lax, 60 to 120 cm. tall; sheaths 

 glabrous to sparsely pilose; blades 

 thin, flat, lax, scabrous, 6 to 12 mm. 

 wide; panicle open, lax, drooping, 15 

 to 30 cm. long, the branches ver- 

 ti dilate, filiform, flexuous, spikelet- 

 bearing toward the ends; spikelets 6 

 to 12 mm. long, with usually 3 

 distant florets, the first longer than 

 the second glume ; first glume narrow, 



