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 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 



margins 2. C. elegans. 



Lemma not conspicuously hairy, the pubescence very short or 

 none. 



Lemma 3-nerved, obovate-cuneate, the apex rounded 3. C. brevisjAca. 



Lemma 7-nerved, broadly triangular, very shortly awned. . 4. C. cucullata. 



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 locality: " Inter Mexico et Queretaro." 



Range: 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. 



3. Chloris brevispica Nash, Bull. Torrey Club 25: 438. 1898. 

 Type locality: Nueces County, Texas. 



Range: 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 locality: "Hab. Mexico boreali. Semina in provincia Tamaulipas prope 

 Matamoros lecta absque nomine misit Dr. Engelmann, 1849." 

 Range: Western Texas and southern New Mexico to Mexico. 

 New Mexico: Roswell; Carlsbad. Plains. 



50. TRICHLORIS Fourn. 



Elect perennials with flat leaves and with many slender spikes digitate or closely 

 approximate at the apex of the culm, forming dense oblong panicles; spikeleta 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 locality: Not stated. 



Range: 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 



