HITCHCOCK — REVISIONS OF NORTH AMERICAN GRASSES. 197 



21. Chaetochloa villosissima Scribn. & Merr. 



Chaetochloa villosissima Scribn. & Merr. U. S. Dept. Agr. Div. Agrost. Bull. 21: 34. 

 /. 19. 1900. "Type specimen collected by J. G. Smith at San Diego, Tex., May, 1897. 

 Limpia Canyon, Presidio Co., 115 (in part) Nealley 1892, a smaller undeveloped speci- 

 men, with much less pubescent leaves, otherwise as in the type. " The type specimen, 

 the original of the illustration, is in the National Herbarium. 



Setaria villosissima Schum. Just's Bot. Jahresb. 28 l : 417. 1902. Based on Chae- 

 tochloa villosissima Scribn. & Merr. 



DESCRIPTION. 



Plants perennial; culms erect or decumbent at base, glabrous, as much as a meter 

 tall, the nodes more or less pubescent; sheaths glabrous or somewhat hispidulous, 

 often scabrous toward the 

 summit, compressed-keeled, 

 especially the lower, hispid 

 on the collar, villous on the 

 margin; ligule densely pi- 

 lose, 2 to 3 mm. long; blades 

 flat, scabrous and villous, or 

 scabrous only, 15 to 30 cm. 

 long, 5 to 8 mm. wide; pani- 

 cles rather loose, more or 

 less interrupted, tapering at 

 the summit, as much as 23 

 cm. long, the branches as- 

 cending, the lower as much 

 as 2 cm. long, the axis angled, 

 scabrous, villous; bristles 

 single below each spikelet, 

 flexuous, antrorsely sca- 

 brous, 1.5 to 2.5 cm. long; 

 spikelets lanceolate-ovate, 

 acutish, not strongly turgid 

 on the convex side, about 3 

 mm. long, pale or greenish; 

 first glume one-third as long 

 as the spikelet, 3-nerved; 

 second glume nearly as long 

 as the fertile lemma, 5- 

 nerved (rarely 7-nerved) ; 

 sterile lemma as long as the 

 fertile, 5-nerved, convex or 

 sulcate, the palea narrow, less than 1 mm. long; fertile lemma lanceolate, the tip 

 rather pointed, incurved, the surface finely but sharply cross- wrinkled. 



This species is little known. The description is drawn chiefly from the type, in 

 which the blades are villous on both surfaces. Nealley's no. 115 (Limpia Canyon, 

 Presidio County, Texas), with only sparingly short-pilose blades, appears to be this 

 species, though the plant -is only 40 cm. tall and the panicle 10 cm. long and few- 

 flowered, the branches very short. Two specimens from Arizona (no definite locality), 

 Emersley 19 and 21 in 1890, may also belong to this species. The blades are scabrous 

 but not villous, and only 3 to 5 mm. wide. The first glume is almost half as long as the 

 spikelet and pubescent near the margins. A sterile specimen from Big Spring, Texas 

 (open woods along stream, 8 miles west of Sterling, Hitchcock 13401), with pubescent 

 blades 1.5 cm. wide, may also belong to this species. 



Fig. 55. — Chaetochloa villosissima. From type specimen. 



