26 POACEAE. 



Calamagrostis rubescens Buckl. Stems tufted, 60-100 cm. tall; stem 

 leaves 3 or 4, 2-4 mm. wide; panicle usually narrow and dense, 8-12 cm. long, 

 erect, pale green, rarely purple, the branches short and flower-bearing to the 

 base; spikelets 3-4 mm. long; lemma shorter than the glumes, obtuse, 4-toothed 

 at apex, bearing a stout, nearly basal, geniculate awn, as long as or longer 

 than itself. The most abundant grass in pine forests. Includes C. suksdorfii 

 Scribn. 



Calamagrostis macouniana Vasey. Stems 60-120 cm. high, erect, slender; 

 leaf blades narrow, flat, long-attenuate, 15-25 cm. long; panicle 10-12 cm. 

 long, purple, narrow or pyramidal, loose, the branches in fives, slender, naked 

 below; spikelets small, 2-2.5 mm. long; lemma equalling the glumes, 2-lobed 

 at apex, bearing a very short straight awn from above the middle of the back. 

 Wet banks of the Palouse at Pullman, not common. 



Calamagrostis canadensis (Michx.) Beauv. Similar to C. macouniana, but 

 usually stouter; panicle looser; spikelets larger. In wet meadows and along 

 streams. 



Calamagrostis canadensis acuminata Vasey. Spikelets larger, 4-5 mm. 

 long. With the species in wet meadows and along streams. 



Calamagrostis neglecta (Ehrh.) G., M. & S. Rootstock slender; stems 

 slender, 40-65 cm. high; leaves soft, 1-3 cm. long, smooth; panicle narrow, 

 glomerate and lobed, 5-10 cm. long; spikelets about 4 mm. long; glumes 

 acute; callus-hairs a little shorter than the floret and as long as those of the 

 rudiment; awn from the middle of the thin lemma or lower, scarcely exceeding 

 it. Spokane County, Suksdorf. 



Calamagrostis hyperborea Lange. Stems tufted, 40-90 cm. high, stiffly 

 erect; leaves stiff, erect, scabrous, somewhat involute; panicle erect, narrow, 

 densely flowered, 8-12 cm. long; glumes scabrous, acute, 4-4.5 mm. long. 

 In wet meadows, Spokane County. 



43. AGROSTIS. 



Annual or usually perennial grasses with small 1 -flowered 

 spikelets, usually in diffuse panicles; glumes membranous, keeled, 

 acute; lemma shorter, obtuse, hyaline, sometimes bearing a dorsal 

 awn; palea shorter than the lemma, sometimes minute or want- 

 ing; grain free, enclosed in the lemma. 



Plants with rootstocks. 



Palea present; panicle usually large. A. alba. 



Palea absent; panicle small. A. pattens. 



Plants tufted, without rootstocks. 

 Panicle loose, open. 



Inflorescence very diffuse; herbage scabrous. A. hyemalis. 



Inflorescence not diffuse; herbage smooth. A. idahoensis. 



Panicle narrow, close. 



Glumes 2.5-3.5 mm. long; panicle 5-30 cm. long; tall 



lowland plant. A. exarata. 



Glumes 2 mm. long; panicle 3-6 cm. long; low alpine 



plant. A. rossae. 



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. Abundantly introduced. 



