HILARIA RIGIDA Crinn-li.) Scrih. (/Vr„,r-/,//;.v ,-;.,/-/o. Tliuil..) 



Pluiii iiereiuiial. rigid, woody tiiroUiL^lioiit. Hxct'|)t tlin yniiiijj; growth, witli 

 li;ird oi'eepiiig roi>tst<)ck sending up scaly hnuiclips. 



C'(////*x spi'eading nr asccndiiin-. l)i-;nicliiiig frrcly. snlid. I to-.'fpi-t lall. Avofilly 

 I...I0W. 



Lfiare.s of ruotstork ai>pressed, sca7-ioiis sc-ales; of culm often ::i-ranked and 

 rather crowded : sheatlis longer than internodes. close, woolly: blades involute, 

 j)ungent, rigid. I to :'. in(dies long; ligule a dense white, woolly coUai-. 



Iiifoir.scriic< a narrow, white or pur])li.sh spike, 'i to ;J inches long, foi-nied 

 of oliovate clusters of :! sessile s))ikelets at each node of the rachis. 



Siiikfilcf-'^: lateral ones in the cluster staniinate and :l- to :!-flowered, middle cue 

 perfect and l-flowered; empty glumes all ahont :> lines long, forming an involucre 

 about the cdustci-; hrst glume of stanunate spikelct oblong, wider above, oblique, 

 conspicufmsly ciliate. 5-nerved, 1 or 3 of the nerves on one side extended in short 

 dorsal awns, second glume ol)ovate, 2-lobed and ciliate ab(n-e, o-to iJ-nerved, with 

 1 or 'i dorsal awns: floral glumes obiong or wedge-shaped, nearly equally 3-lobe(l 

 at apex or merely o})tuse, ciliate, o-nerved. midnerve slightly excurrent, and one 

 lateral nerve rather oljscure, 2 to 3^ lines long: palet oblong, truncate, slightly 

 scabrous on the two nerves above. 2 lines long; empty glumes of perfect 

 flower equal, at the back of the chister, narrow, cuneate. obliqiie above, 4 to 

 (i awned, ciliate. 3 to 3 lines long including awns; floral glume oblong, equally 

 3-lobed, ciliate, 3 to 3 lines long, 3-nerved, lateral nerves equal and slightly excur- 

 rent. midnerve excurrent in an awn 4- to 1 line long; palet lance-oblong, obtuse, 

 ciliate or lacerate at apex, 3-nerved, 3 to 3 lines long; stigmas 3, long, plu7iiose. 



Grninfi: no mature grains found. 



Plate II; a to d. parts of staniinate flower: a. first empty ghime; b. second 

 empty glume; c. floral glume: <7. ])alet; e, perfect flower with its two empty 

 glumes; /to /(, parts of perfect flower; /, floral glume; (/. jialet: /(. empty glume. 



New Mexico and Arizona; almost the only grass on tlie driest desert land; 

 commonly called Gayetta grass. It is considered a valuable grass. 



