GRIFFITHS THE GRAMA GRASSES. 



abundant and conspicuous plant, easily recognized by its long, delicate, graceful 

 culms, small spikes, tufted habit and narrow, flat, hairy, abundant leafage. In 

 minuter details it differs from all other species of the genus in having the lateral awns 

 of the lemmas of the second floret split into 2, making a well-developed 5-awned 

 lemma, while the lower florets are typically 3-awned, and the lateral awns of the 

 lemma of the third floret and rarely of the second also are split into 3, making it 7-awned 

 and 7-nerved. 



It is very probable that this characterization will have to be modified when mature 

 material becomes available, for the above collections are of plants in bloom only. 



3. Cathestecum erectum Vasey & Hack. 



Cathestecum erectum Vasey & Hack. Bull. Torrey Club 11 : 37. pi. 45. 1884. The 

 Havard specimens from Presidio County, western Texas, no. 30, 1881, and no. 2, 1883, 

 are in the U. S. National Herbarium, together with the Palmer specimen from Sonora, 

 Mexico, 1869, which is the first mentioned, There is a note on Havard 's no. 30 in 



Fig. 25. — Cathestecum erectum. a, b, Short and long-awned forms of spikelet; c, uppermost 

 spikelet of a; d, e, lemma and palet of first floret;/, g, lemma and palet of second floret; h, i, 

 lemma and palet of third floret; j, 7c, two views of caryopsis. a, 6, Scale 5; c-i, scale 7.5; j, fc, 

 scale 10. From Griffiths 6834. 



Vasey's hand, "=17 Dr. Palmer 1869." See also U. S. Dept. Agr. Div. Bot. Bull. 

 12*: pi. 13. 1890; Contr. Nat. Herb. 2 : 536. 1894. 



This is the species described and figured a by Scribner under the name Cathestecum 

 prostratum Presl. 



DESCRIPTION. 



A sparsely hairy, erect, stoloniferous perennial of variable habit, 5 to 40 cm. high; 

 culms erect or geniculate and rooting at the prominently hairy nodes, simple or 

 branched; sheaths sparsely hairy, the ligule a line of long white hairs; blades flat, 

 very variable, abundant below, shortened upward, bearing a few scattered hairs like 

 those on the sheaths, scabrous-margined; panicle racemose, 3 to 5 cm. long, the apex 

 of the axis minutely bifurcated; spikes 6 to 8, about 8 mm. long, rather thin, but not 

 especially lax; the upper spikelet perfect, the lateral pair rudimentary; lower florets 

 of the lateral spikelets with well developed but sterile lemmas; second floret stami- 

 nate or neuter, the upper rudimentary; first glume of each spikelet reduced to a 

 short, ti'uncate, nerveless scale, the second long, lanceolate, keeled, hairy, mucro- 

 nate, 3 to 4 mm. long; lemma coriaceous, smooth, with awns and lobes about equal, 

 but the awns slightly longer, in the upper florets the lobes deeper and the awns with 

 long hairs below; palet slightly shorter than the fertile lemma, plicate, short-awned; 

 caryopsis obovate, 1.5 mm. long, flattened, the scutellum covering about three-fourths 

 the ventral surface. (Figure 25.) 



■ aU.S. Dept. Agr. Div. Agrost. Bull. 7 : 242./. 224. 1897. 



