60 CONTRIBUTIONS FROM THE NATIONAL, HERBARIUM. 



compressed, glabrous or hairy on the margin toward the summit, rarely 

 sparsely pilose; ligule ciliate, about 1 mm. long; blades commonly 6 to 20 cm. 

 long and 3 to 8 mm. wide (extremes larger or smaller), usually rather stiff, but 

 sometimes lax, flat, tapering from the rounded base to a more or less involute or 

 folded summit, glabrous beneath, scabrous and sparsely pilose on the upper sur- 

 face, at least toward the base; spikes finally rather long-exserted, 3 to 10 cm. 

 long (commonly not over 7 cm. long), not very dense, the axis strongly flexuous, 

 scabrous ; burs truncate at base, the body 4 to 7 mm. high, as broad or broader, 

 pubescent, tawny or plumbeous, the outer slender bristles on the average less 

 numerous and relatively shorter than in C. viridis, the inner stout, broadened at 

 base, the longest of them usually about equaling the lobes of the body but some- 

 times longer or sometimes much reduced, ascending or spreading, the lobes of 

 the body commonly 10, erect or bent inward or sometimes one or two lobes in- 

 flexed, often with one or two green lines down the back, the tips hard and spine- 

 like, retrorsely barbed ; spikelets 3 to 6, usually 4, about equaling the lobes or 

 shorter, 4.5 to 6 mm. long, about one-third as wide ; first glume narrow, 1-nerved ; 

 second glume two-thirds to three-fourths as long as the subequal sterile lemma 

 and fruit, the summit of the fertile lemma submembranaceous, the 3 nerves 

 usually obvious. 



Throughout the range of this species the burs vary greatly in size; as 

 Sloane, 1 writing of the grass in Jamaica, expresses it: "Of this there are of 

 various bignesses." Mexican plants are on the average more robust than those 

 of the United States and the West Indies, with blades often 10 to 12 mm. wide, 

 and burs 6 to 7 mm. wide (excluding the bristles), but occasional United 

 States and West Indian specimens are about as robust as any of the Mexican 

 plants. 



In a few West Indian specimens the burs are depauperate, only 2 or 3 mm. 

 wide and with but one or two spikelets. In most of these specimens, however, 

 normal or nearly normal burs are found on the same plant. 



DISTRIBUTION. 



Open ground and waste places, from South Carolina to New Mexico and 



south to Uruguay ; a common weed throughout the warmer part of its range ; 



sparingly introduced in Hawaii, the Philippines, and Samoa. 



South Carolina: Aiken, Ravenel in 1869. 



Georgia : Darien, Smith 2151. 



Florida : Jacksonville, Combs 42 ; Curtiss 3619, 4042, 5152. Duval County, Fred- 

 holm 5236. Madison County, Combs 218 ; Hitchcock 2281. Monticello, Combs 

 339. Wewahitchka, Biltmore Herb. 1883a. Lake City, Hitchcock 2278; 

 Combs & Rolfs 150 ; Quaintance 853 ; Ricker 877. Gainesville, Chase 4226. 

 Archer, Quaintance 816. Eustis, Hitchcock 2279; Nash 189, 1134, 2100. 

 Grasmere, Combs & Baker 1046. Ouasi, Baker 7. Jensen, Hitchcock 739. 

 Miami, Amer. Gr. Nat. Herb. 615 ; Eaton 93 ; Hitchcock 663. Key Largo, 

 Pollard, Collins & Morris 167. Lakeland, Hitchcock 830. Marco, Standley 

 12736. Fort Myers, Standley 12834; J. P. Standley 357; Hitchcock 448. 

 Manavista, Tracy 7046. Newport, Pollard, Collins & Morris 167. Key 

 West, Hitchcock in 1906. Fellsmere, Tracy 9387. Sneeds Island, Tracy 

 6.112. 



Texas : Del Rio, Hitchcock 13633. Without locality, Nealley in 1890 and 1893. 



New Mexico: Without locality, Fendler 983. 



Lower California : Comondu, Brandegee 4. Santa Agueda, Palmer 220 in 1890. 

 San JosS del Cabo, Purpus 320. 



] Voy. Jam. 1: 108. 1707. 



