HORDEAE 149 



Sitanion longifoHiim, a grass that so far as we know has 

 received no common name. As used here the name given 

 above is intended to cover what Mr. J. G. Smith beheved to 

 be two species, one of which he called S. longifolmm and 

 the other 5. hrevifoliuin. We are unable to separate them in 

 any way but arbitrarily, though extreme forms would seem dis- 

 tinct enough. Possibly further study will show that Mr. 

 Smith was correct. The grass in question is a tufied perennial 

 from 8 to 15 inches high, depending upon the amount of 

 water it gets. Its stems are erect; there are several from a 

 root, each terminated by a head which roughly resembles a 

 head of bearded wheat, with unusually small grains. In very 

 dry situations the grass has a grayish color due to the "bloom" 

 on the leaves and stems Where it receives more water it 

 is greener. When mature the awns or "beards" are widely 

 spreading and the small branches of the panicle break up» 

 setting free the whole spikelet instead of merely the mature 

 grain as is commen in most of the grasses. 



It is probable that Sitanion puhiflorum is much more 

 common in the State than is indicated by the collections, but 

 has been confused with the preceding and not collected. It 

 has been the custom to consider all the species of the genus 

 but forms of an extremely variable species and refer all of 

 them to a single species and make few collections. None of 

 these grasses are very important as forage plants since stock 

 do not seem to care much for tliem. The other two species 

 here listed are rare in the western side of the State which they 

 enter from Arizona. 



Tribe IX. HORDEAE. 



Splkelets usually single at the node55 of the 

 rachis. (Compare Hordeum.) 

 Empty glumes with their sides turned to- 

 ward the rachis. OS. Agp.optron. 



Empty glumes with their backs turned to- 

 ward the rachis. A single species. 70. Lolium. 

 Spikelets 2 to 6 at each joint of the rachis, or 

 if solitary the empty glumes arranged ob- 

 liquely to the rachis. 

 Spikelets 1-flowered or with a rudimentary 



.second flower. •;:). Houdecm. 



