POACEAE. 43 



Agrostis aequivalvis Trin. Tufted; stems slender, 30-60 cm. high; blades 

 narrow, 1 mm. wide; panicle open with slender branches; glumes equal, acute; 

 lemma obtuse, awnless. 



Alaska to Oregon. 



Agrostis thurberiana Hitchc. Stems tufted, 20-40 cm. high; blades 2-4 

 mm. wide; panicle narrow, loose, usually drooping; glumes equal; lemma 

 obtuse, S-nerved. 



In wet places in the mountains, rare. British Columbia to California and 

 Utah. 



Agrostis glomerata (Presl.) Kunth. (A. infiata Scribn.) Perennial; stems 

 erect, 20-30 cm. high, scabrous near the panicle; leaf sheaths striate, often 

 inflated; blades 2-8 mm. wide; panicle spike-like, 2-7 cm. long, often lobed 

 spikelets 3 mm. long; glumes equal, scabrous on the keel, sharp-pointed 

 lemma 2 mm. long, awnless or with a short awn from the middle of the back 

 callus hairs short. 



Along the seacoast, rare; Vancouver Island to northern California; probably 

 only a subspecies of A. exarata Trin. 



Agrostis stolonifera L. (A. verticillata Vill.) Stems 20-80 cm. high, 

 often decumbent at base, sometimes stoloniferous; leaf blades pale, acute, 3-4 

 mm. wide; panicle dense, verticillate or lobed, 3-10 cm. long, usually pale 

 green; branches floriferous to the base; glumes equal, obtusish, 2 mm. long; 

 lemma 1 mm. long, awnless, truncate and toothed at the apex; palea nearly as 

 long as the lemma. 



In wet places, sparingly introduced from Europe. 



Agrostis maritima Lam. Tufted, the stems decumbent or spreading; 

 leaves numerous, very short; ligules 2-3 mm. long; panicle narrow, 2-5 cm. 

 long; lemma obtuse, the midvein protruding in a minute point. 



In moist places near the seashore. 



Agrostis alba L. Redtop. Perennial with creeping rootstocks; stems 

 erect, 50-100 cm. tall; leaf blades flat, usually scabrous, the sheaths smooth; 

 panicle 7-25 cm. long, open at first, then contracted, greenish or purple; palea 

 present, one-third to one-half the length of the lemma. 



Common in fields and meadows, especially in wet places. 



Agrostis humilis Vasey. Stems 10^10 cm. high; panicles narrow, 2-8 cm. 

 long, usually purple; glumes equal; lemma awnless. 

 At high elevations in the mountains. 



Agrostis hallii Vasey. Stems erect, 60-80 cm. high; blades rather broad; 

 ligule elongate; panicle narrow, 10-12 cm. long; spikelets pale; glumes acumi- 

 nate, about 4 mm. long; lemma awnless, the hairs at the base nearly half as 

 as long. 



Oregon and California. 



Agrostis pallens Trin. Stems 30-90 cm. tall; blades rather narrow; panicle 

 narrow, loose or in seashore forms contracted, pale green; spikelets 2.5-3 mm. 

 long; glumes equal; lemma awnless or with a minute awn. 



Not common, but very variable. 



Agrostis foliosa Vasey. Very similar to A. pallens Trin. but stems taller, 

 50-120 cm. high; panicle open, with stiff ascending branches; lemma awnless 

 or with a straight or bent awn. 



In open places, British Columbia to California. 



Agrostis microphylla Steud. {A. ampla Hitchc.) Stems 30-90 cm. 

 tall; blades flac, 2-8 mm. wide; panicle narrow, compact, pale green; glumes 

 acute, subequal; lemma one-third shorter. 



In open ground, not common. 



