WOOTON AND STANDLEY FLORA OF NEW MEXICO. 49 



Spikelets 2 to 6 at each joint of the rachia or if solitary 

 the glumes arranged obliquely to the rachis. 

 Spikelets 1-flowered or with a rudimentary second 



flower 72. Hordeum (p. 106). 



Spikelets 2 to many- flowered. 



Rachis of the spikes jointed, readily breaking 



into joints 73. Sitanion (p. 107). 



Rachis of the spikes continuous, not breaking 



into joints 74. Elymus (p. 108). 



1. TKIPSACITCVI L. 



Tall stout perennial with creeping rootstocks, broad flat leaves, and terminal digitate 

 inflorescence, the spikes separating into joints at maturity; spikelets unisexual, the 

 staminate in pairs at the joints of the rachis above, the pistillate solitary, embedded 

 in each joint of the rachis below in the same inflorescence; glumes of the staminate 

 spikelet subcoriaceous, those of the pistillate spikelet finally cartilaginous, the lemmas 

 and paleas hyaline. 



1. Tripsacum lanceolatum Rupr.; Fourn. Mex. PI. 2: 68. 1886. 

 Type locality: Aguas Calientes, Mexico. 

 Range: Southwestern New Mexico to southern Mexico. 

 New Mexico: Guadalupe Canyon (E. C. Mcrton 2035). 



2. TRACHYPOGON Nees. 



Rather tall perennials with narrow leaves and usually solitary, long-exserted 

 racemes; spikelets 1-flowered, in pairs at the nodes of the imperfectly jointed rachia, 

 one nearly sessile, awnless, sterile, the other pedicellate, fertile, long-awned; glumes 

 rigid, the outer large and inclosing the other; lemmas produced into long twisted 

 geniculate awns. 



1. Trachypogon montufari (H. B. K.) Nees, Agrost. Bras. 312. 1820. 



Andropogon montafari IT. B. K. Nov. Gen. & Sp. 1: 184. 1816. 



Type locality: "In aridis, apricis rcgni Quitensis prope Conocoto, Pintae et Mi- 

 lam Chilloensem Montufari." 



Range: New Mexico and Arizona to Mexico and South America. 



New Mexico: Near "White Water (Mearns 353). Dry hills. 



3. ELYONUPvTJS Humb. & Bonpl. 



Low or tall annuals or perennials with rather rigid leaves and solitary te rminal 

 racemes; spikelets L-flowered, awnless; first glume rigid or eous, 2-toothed 



at the apex, the margins inflexed, more or less ciliate, with balsam-bearing lines 

 between tin" lateral keels, the second a little shorter than the first, acute; lemma 

 delicate and hyaline; palea minute or none; stamens 3; styles distinct. 



1. Elyonurus barbiculmis Hack. Ld DC. Monogr. Phan. 6:330. 1889. 

 Tvi'i; locality: Western Texas. 



Range: Southern Ne'vi Mexico and Ajizona to western Texas and adjacenl Mexico. 

 New Mexico: Dog Spring (Mearna 2376). Dry hills. 



4. SCHIZ ACH YRIUM Nei ORASS. 



Tall perennials, tufted or Erom rootstocks, with Mat or Involute leaves, and spikelike 

 solitary raceme-; terminating the stem or its branches; Bpikelets in pair- ;ii each node 

 of the jointed and often hairy rachis. one sessile and fertile, the other pedicellate and 

 sterile; glumes indurated 9ometim< pubescent; lemma entire or 2-toothed at the 



apex, bearing a straij hi . conl rted, or spiral awn; palea small, hyaline; sta ru I to 



3; st_\ les distini I 



r,LT,70 o — 15 4 



