150 



POACEAE 



3. Agrostis thurberiana Hitchc. 



Thurber's Bent-grass. 



Fig. 330. 



Agrostis thurberiana Hitchc. U. S. Dept. Agr. Bur. PI. Ind. 

 Bull. 68: 23. pi. L f. 1. 1905. 



Culms slender, in small tufts, erect, 20-40 cm. tall ; 

 panicle rather narrow, lax, more or less drooping, 

 5-7 cm. long ; leaves somewhat crowded at base, the 

 blades about 2 mm. wide ; spikelets green or pale, 

 rarely purple, 2 mm. long ; lemma nearly as long as 

 glumes, the palea about two-thirds as long ; rachilla 

 prolonged behind the palea as a minutely hairy 

 pedicel, .3 mm. long. 



Bogs and moist places in the Hudsonian Zone; British 

 Columbia to Montana, and south to Sequoia National Park. 

 July-Aug. Type locality: Skamania County, Washington. 



4. Agrostis verticillata \ ill. 



Water Bent-grass. 



Fig. 



331. 



62. 17S3, in part, but not 

 PI. Dauph. 16. 1779. 



Agrostis stolonifera L. Sp. PI. 



as to the Swedish plant. 

 Agrostis verticillata Vill. Prosp. 



Culms usually decumbent at base, sometimes 

 with long creeping and rooting stolons ; panicle 

 contracted, lobed or verticillate, especially at base. 

 3-10 cm. long, light green or rarely purplish, the 

 branches spikelet-bearing from the base ; glumes 

 equal, obtuse, scabrous on back and keel, 2 mm. 

 long; lemma 1 mm. long, awnless, truncate and 

 toothed at apex ; palea nearly as long as the lemma. 

 Resembles in habit Polypogon lutosus, which differs 

 in having awned glumes and lemma. 



Moist ground, especially along irrigation ditches, in the 

 Sonoran Zone; Central California to Te.xas and Mexico; 

 also at Linnton, Oregon (Nelson) ; introduced from Europe. 

 May-June. Type locality, European. 



5. Agrostis hiimilis Vasey. 

 Mountain Bent-grass. Fig. 332. 



Agrostis humilis Vasey, Bull. Torrey Club 10: 21. 1883. 



Culms slender, tufted, erect, 5-30 cm. tall ; leaves mostly 

 basal, the blades flat, thin, 2-10 cm. long, as much as 2 

 mm. wide; panicle 2-8 cm. long, rather open or in dwarf 

 plants narrow; spikelets usually purple. 1.5-2 mm. long; 

 glumes equal, rather broad, abruptly pointed, smooth or 

 slightly scabrous on the upper part of the keel; lemma 

 awnless, nearly as long as the glumes ; palea usually about 

 two-thirds as long as the lemma. 



Wet places in mountain meadows in the Alpine Zone; British 

 Columbia to Oregon and Colorado. July-Aug. Type locality: 

 Mount Adams. 



