298 GRAMINE^. Aira. 



as tlie upper lloret. — n. Bor.-Am. ii. 243, t. 228; Torr. in Pacif. 11. Hep. iv. 155. 

 JJeschainjisia elongata, Munro in Eenth. I'l. Ilartweg. 342. 



San Francisco {Bolandcr, n. 15"2o, 6080) ; northwunl to Oic;?on, Ilall, Iloircll. Very variable 

 in heiglit ; soiiictinios purplisli, but usually of a very bright but pale green. As noted by Torrey, 

 1. c, Hooker's otiierwise exeellfiit tigure lacks the consiiicuous rudiment. 



4. A. danthonioides, Trln. Culm slender, from a few inches to 2 feet liigli, 

 sometimes genieiilate and s|)aringly branclied beluw : leaves veiy narrow, those of 

 the culm 1 or 2 inches long, with elongated ligules : panicle very loose and open, 

 about J the lengtii of the culm, the lowermost rays in threes, the others in pairs or 

 solitary, distant, mostly spreading and few- (about 5-) flowered above the middle : 

 glumes 3 lines long or more, lineardancoolate, acuminate, 3-nerved, green and rough 

 on the keel : lower floret on a brief callus, the upper raised to the middle of the 

 lower ; lower palet a little over a line long, tiie hairs at base \ as long, shining below, 

 its truncate apex witli 4 mrnutely ciliate teeth ; awn inserted just below the middle, 

 about 3 times its length, light bnnvn, twisted below and geniculate near the middle. 

 — Mem. Acad. St. Peterrfb. 1831, 57, and Icon. t. 255. Deschampsia calycina, 

 Presl, Rel. Hteuk. i. 251. D. danthonioides, Munro in IJenth. PI. Hartweg. 342. 

 Trisetnm glahnim, Buckl. in Proc. Acad. Philad. 1862, 100 ; Gray, in same, 337. 



Monte Diablo (Ureivcr, n. 1183) ; Oakland, etc. {Bolander, n. 6072) ; Sierra Nevada (Zemmod) ; 

 northward to ()iV','on {Xiittall, IJa/l) and eastward to Texas. Accoriling to Mr. liolander it is 

 very abundant in some moist localities, Ibrniing the bulk of the herbage. 



5. A. latifolia, Hook. Cuba from 1 to 2 feet high, its lower leaves 2 or 3 

 inches long and about 3 lines witle, ihit ami smooth ; panicle at lirst inchuknl below, 

 ■with few slender rays which are densely llowered above ; spikelets very broad and 

 flattened : glumes about 3 lines long, ovate-lanceolate, acuminate, rough on the keel 

 above : lower palet about a line long, its silky hairs lialf as long or more, very broad, 

 irregularly 4-toothed and minutely pubescent above ; awn stout, attached just above 

 the middle, somewhat divergent, exceeding the palet but included by the glumes : 

 the second floret upon a very short joint which reaches only about one-fourth tlie 

 length of the lower floret ; upper joint or rudiment very brief, but manifest. — Fl. 

 Bor.-Am. ii. 243, t. 227. 



Oregon (Hall) ; Wasliington Territory (Cooper) ; Rocky Moimtains. Tliis has not been detected 

 within the State, but is likely to occur in the northern portion. In his description Hooker gives 

 the awn as inserted below the nudille, but figures it correctly. 



36. ARRHENATHERUM, Bcauv. Oat-Gkass. 



Panicle open. Spikcdcts subterete, 2 llowered, with the rudiment of a third. 



Lowest flower staminafe, with a long bent awn below the middle of the back. Second 



flower perfect, its lower palet bristle-pointed from near the tij). Otherwise as Ai'ena. 



A genus of n single species, which is sometimes included in Avcna, from whicli it is separated 

 by liaving its lowest tlower staniinate. 



1. A. avenaceum, Beauv. Culm perennial, 2 to 4 feet high, with broad flat 

 soft leaves ; panicle (i to 8 inches long, narrow, spreading in flower : spikelets 4 or 5 

 lines long, i)ale and shining : lower glume about half as long as the upper, which 

 et^uals the florets : lower palet of staminate flower about 5-nerved, its awn twice its 

 length ; that of the upper floret 7-nerved, both hairy near the base. — Agrost. 55, 

 t. 11, fig. 5 ; Reichenb. Icon. Fl. Germ. t. 104. 



A native of Europe and naturalized as a weed ; occasionally sown as a meadow grass in the older 

 States. 



37. HOLCUS, binn. Vklvet Guass. 



Spikelets crowded on the branches of an open panicle and jointed upon their pedi- 

 cels, compressed, 2-lU)wered. Glumes boat-shaped, membranaceous, exceeding the 



