AVEXK.K. 



363 



Delioiito iiiimuils with tlio habit of .lira, liiivin<f iiurrow ca'sj)!- 

 toso bUidos. I'liiiicle slciidtT, coiitriictod, with ca|iiliiiry nivs. 

 SjM'cios 2, I'ouiul ill till" vicinity of tlio Muditernmouu tst'iuiiul north- 

 Wiiril and introduced intootiior countries. 



Tlic rachillii is continuous aa in J)<'srhiiin/>si((, hut tlu' ji^cnus is 

 readily distinguished by the peculiar club-shaped awn of the lloral 

 glume. 



1. \V. CANMSCENS Beruh. 1. c. Coryncphnrus canesccns lieauv. 

 Agrost. 159 (ISia). 



Tufted glaucous or slight iy purplish. 20-150 cm. high, with 

 tine still" convolute blades, the lower 5- 

 10 cm., those on the culm about 1 cm. 

 long. I'anicle 4-0 cm. long. Spike- 

 lots about :{ mm. long: cm[)ty glumes 

 pointed, coiu'ealing the florets, awn 

 scarcely protruding; lloral glmne l.a 

 mm. long. 



In saiuly soil. Tntroduced into the 

 Unite(l States with grass-seed. 



70. (154). DeschaMPSIA Heauv. 

 Agrost. 01 . /. S. /'. :5 (lcSl2). A iridimn 

 Steud. Syn. PI. f J ram. 423 (1S54). There arc at least 10 other 

 synonyms. 



S[)ikelets 2-flowered. in a loose or rarely contracted panicle with 

 sleiuler rays, rachilla articulate, hairy, more or less produced 

 between the floral glumes and beyond the upper one as a hairy 

 bristle, or rarely bearing an empty glume, Km})ty glumes keeled, 

 rather acute, the sides thinly scarious; lloral glume membranous or 

 nearly hyaline, ibtuse or truncate, 2-to several-toothed, with aline 

 dorsal awn attached near tlu^ middle, the lower lloret sessile, the 

 ui))H'r raised on a stipe; palea narrow, prominently 2-nerved, often 

 '.'-^oothed. Stamens 3. Stylos short, distinct. (Jrain enclosed, 

 but u'uallv not adherent. Perennial grasses with the shinin<r 

 spikolett, of Tb'isi'fum and Ai'ra, usually smaller than the former, 

 larger th in those of the latter genus. There are about 20 s])ocies, 

 gonerjilly distributed over the temperate regions of the northern 



Fio. 64. — Weittgai'tneria 



citnesc('.)is. Spikelct. 



(ScriliiuT. ) 



