62 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



New Mexico: Trout Spring; Pecos Baldy. Meadows, in the Hudsonian and 

 Arctic-Alpine zones. 



23. LYCURUS II. B. K. 



Cespitose erect perennial with narrow or convolute leaves and densely flowered 

 cylindrical spikelike terminal panicles; spikelets 1-flowered, usually in pairs; glumes 

 nerved, the nerves often produced into awns; lemma 3-nerved, awned, broader and 

 longer than the glumes; palea 2-nerved, 2-keeled; stamens 3; styles short, distinct; 

 grain included within the glumes, free. 



1. Lycurus phleoides H. B. K. Nov. Gen. & Sp. 1: 141. pi. 45. 1816. 



Texas timothy. 



Type locality: "Crescit in temperatis Mexici, inter Guanazuato et Temescatio 

 et in radicibus aridissimi montis La Buffa, alt. 1030 hexap." 



Range: Western Texas and southern Arizona to Mexico. 



New Mexico: Abundant from the Mogollon Mountains and Santa Fe and Las 

 Vegas mountains southward and eastward across the State. Dry hills, in the Lower 

 and Upper Sonoran zones. 



Texas timothy is abundant on the dry hills of the southern part of the State. It is 

 less common in the north. It grows in bunches and is a rather important range grass 

 in some sections. 



24. ARISTIDA L. Needle grass. 



Tufted annuals or perennials with narrow leaves; spikelets 1-flowered, on long or 

 short slender pedicels, in more or less expanded terminal panicles; rachilla articulated 

 above the glumes and produced into a hard obconical hairy callus below the lemma 

 but not extending beyond it; glumes more or less unequal, acute or bristle-pointed, 

 slightly keeled; lemma somewhat firmer in texture, closely rolled around the floret 

 and the usually short palea, terminating in a usually trifid awn; grain slender, tightly 

 inclosed in the hardened lemma but free from it. 



key to the species. 



Annual 1. A. bromoides. 



Perennials. 



Plants widely divaricate-branched, the branches of the panicle 

 rigid and straight. 



Awns 3, all of about the same length 2. A. divaricata. 



Awns apparently 1, the lateral ones short or obsolete 3. A. schiediana. 



Plants with erect or at most rather weakly spreading stems. 

 Glumes nearly equal. 



Plants stout and strict, 30 cm. high or more; pedicels 



short, straight; glumes conspicuously awned 4. A.arizonica. 



Plants slender, 20 cm. high or less, rather spreading; 

 pedicels slender, sinuous; glumes acuminate, 



not awned 5. A. havardii. 



Glumes very unequal, the first usually about half as long 



as the second. 



Mature lemma not tapering upward, the neck of about 



the same diameter as the base; second glume 



considerably longer than the lemma, the latter 



smooth; awns 6 to 8 cm. long 6. A. longiseta. 



Mature lemmas tapering upward into a slender neck; 

 second glume barely surpassing the lemma, 

 usually shorter, the lemmas usually 6cabrous; 

 awns usually much less than 6 cm. long. 



