WOOTON AND STANDLEY—FLORA OF NEW MEXICO. 49 
Spikelets 2 to 6 at each joint of the rachis or if solitary 
the glumes arranged obliquely to the rachis, 
Spikelets 1-flowered or with a rudimentary second 
flower........2-. 20-2222 e ee ee eee eee eee ee 72. HorpEvm (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, Evymus (p. 108). 
1. TRIPSACUM 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. Pl. 2: 68. 1886. 
Type Locauity: Aguas Calientes, Mexico. 
Rance: Southwestern New Mexico to southern Mexico. 
New Mexico: Guadalupe Canyon (£. C. Merton 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 rachis, 
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. 342. 1829. 
Andropogon montufari H. B. K. Nov. Gen. & Sp. 1: 184. 1816. 
TyprE Locatity: “In aridis, apricis regni Quitensis prope Conocoto, Pintae et Vil- 
lam Chilloensem Montufari.”’ 
Rance: New Mexico and Arizona to Mexico and South America. 
New Mexico: Near White Water (Mearns 353). Dry hills. 
8. ELYONURUS Humb. & Bonpl. 
Low or tall annuals or perennials with rather rigid leaves and solitary terminal 
racemes; spikelets 1-flowered, awnless; first glume rigid or subcoriaceous, 2-toothed 
at the apex, the margins inflexed, more or less ciliate, with balsam-bearing lines 
between the lateral keels, the second a little shorter than the first, acute; lemma 
delicate and hyaline; pale&é minute or none; stamens 3; styles distinct. 
1. Elyonurus barbiculmis Hack. in DC. Monogr. Phan. 6: 339. 1889. 
TypE Locatity: Western Texas. 
RANGE: Southern New Mexico and Arizona to western Texas and adjacent Mexico. 
New Mexico: Dog Spring ( Mearns 2376). Dry hills. 
4, SCHIZACHYRIUM Nees. SaGE GRass. 
Tall perennials, tufted or from rootstocks, with flat or involute leaves, and spikelike 
solitary racemes terminating the stem or its branches; spikelets in pairs at each node 
of the jointed and often hairy rachis, one sessile and fertile, the other pedicellate and 
sterile; glumes indurated, sometimes pubescent; lemma entire or 2-toothed at the 
apex, bearing a straight, contorted, or spiral awn; palea small, hyaline; stamens 1 to 
3; styles distinct. 
52576°—15—-4 
