88 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
KEY TO THE SPECIES. 
Spikes slender, naked or interrupted at the base; panicle of more 
than a single verticel of spikes........ eee eee eee eee eee ee ee 1. C. verticillata. 
Spikes stout, spikelet-bearing to the base; panicle of a single ter- 
minal verticel of spikes. 
Lemma conspicuously hairy, long-villous on the nerves and 
MAMQINS. 2.2. eee cee eee eee cece eee eee 2. C. elegans. 
Lemma not conspicuously hairy, the pubescence very short or 
none. 
Lemma 3-nerved, obovate-cuneate, the apex rounded..... 3. C. brevispica. 
Lemma 7-nerved, broadly triangular, very shortly awned.. 4. C. cweullata. 
1. Chloris verticillata Nutt. Trans. Amer. Phil. Soc. n. set, 5: 150. 1837. 
TYPE Locality: ‘On the sandy banks of the Arkansas, near Fort Smith.”’ 
RanGE: Kansas and Texas to New Mexico. 
New Mexico: Pecos; Clayton; Redlands; Socorro; Nambe Valley. Dry plains 
and hills, in the Upper Sonoran Zone. 
2. Chloris elegans H. B. K. Nov. Gen. & Sp. 1: 165. 1816. 
Type Locauity: ‘‘ Inter Mexico et Queretaro.” 
Ran@e: Texas and Arizona to Mexico. 
New Mexico: Common from Silver City, Socorro, and Roswell southward. Plains 
and river valleys, in the Lower and Upper Sonoran zones. 
Often a troublesome weed in alfalfa fields. 
. Chloris brevispica Nash, Bull. Torrey Club 25: 438. 1898. 
TYPE LOCALITY: Nueces County, Texas. 
RanGeE: Western Texas to southeastern New Mexico. 
New Mexico: Roswell (Griffiths 5710, 5746). Sandy soil. 
4. Chloris cucullata Bisch. Ann. Sci. Nat. III. Bot. 19: 357. 1853. 
CROWFOOT GRAMA. 
Type Locatity: “Hab. Mexico boreali. Semina in provincia Tamaulipas prope 
Matamoros lecta absque nomine misit Dr. Engelmann, 1849.”’ 
RanGeE: Western Texas and southern New Mexico to Mexico. 
New Mexico: Roswell; Carlsbad. Plains. 
50. TRICHLORIS Fourn. 
Erect perennials with flat leaves and with many slender spikes digitate or closely 
approximate at the apex of the culm, forming dense oblong panicles; spikelets 1 to 
3-flowered, hermaphrodite, sessile in 2 series along the continuous rachis of the uni- 
lateral spikes; rachilla articulated above the glumes and prolonged above the hermaph- 
rodite flowers, terminating in an awned rudimentary floret; glumes unequal, 1-nerved, 
membranaceous, the second short-awned; lemmas membranaceous, 3-nerved, 3-awned, 
the awns erect, subequal or the lateral ones much shorter; palea hyaline, 2-keeled; 
stamens 3; styles distinct; grain narrow, oblong, free. 
1. Trichloris fasciculata Fourn.; Benth. Journ. Linn. Soc. Bot. 19: 102. 1881. 
TypE Loca.ity: Not stated. 
Ranae: Western Texas to New Mexico and Mexico, 
New Mexico: Mesilla Valley. Sandy mesas, in the Lower Sonoran Zone. 
51. PAPPOPHORUM Schreb. 
Cespitose perennial with narrow, usually convolute leaves and spikelike panicles; 
spikelets 1 or 2-flowered; rachilla jointed above the glumes, these persistent, mem- 
branaceous, acute, carinate, nerveless, or with 1 to 3 nerves on each side; lemmas 
