MANUAL OF THE GRASSES OF THE UNITED STATES 335 



21. Agrostis rossae Vasey. Ross redtop. (Fig. 680.) Culms 10 

 to 20 cm tall, densely tufted; blades mostly not more than 1 mm 

 wide; panicle contracted, 2 to 6 cm long, the branches appressed; 



Figure 678.— Distribution of 

 Agrostis diegoensis. 



Figure 676.— Agrostis pattens. Plant, X 1; glumes and floret, X 5. (Howell, Oreg.) 



spikelets green or purple, about 2 mm long; lemma 1.5 mm long, 

 awnless; palea minute. 91 —Rocky creeks and mountain slopes 

 at high altitudes, Colorado and Utah to Alberta, Washington, and 

 California. (Fig. 681.) Differs from A. exarata 



in the hard 

 tufted base, 

 the smaller 

 size and the 

 narrower few- 

 er-flowered 

 panicle with 

 appressed 

 branches. What appears 

 to be an awned form oc- 

 curs in Colorado (Breck- 

 enridge and Mount Mas- 

 sive) and British Columbia 

 (Revelstoke). 



22. Agrostis exarata 

 Trin. Spike redtop. 

 (Fig. 682, A) Culms 20 to 

 120 cm tall, mostly tufted, figure 679. 

 sheaths smooth or some- 

 what scabrous; ligule 



Figure 677. — Agrostis diegoensis 

 glumes and floret, X 5. 



Plant, X 1; 

 (Orcutt, Calif.) 



Agrostis bias- 

 dalei. Pani- 

 cle, X 1; 

 - glumes and 



prominent; blades flat, 1 to floret, x 5. 



o -l -l (Type.) 



8 mm wide ; panicle narrow, 

 from somewhat open to close and spikelike, sometimes interrupted, 

 1 to 25 cm long; glumes acuminate or awn-pointed, nearly equal, 2.5 

 to 4 mm long, scabrous on the keel and often scaberulous on the back; 

 lemma about 2 mm long, awnless or bearing from about the nuddle 



55974° 



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