HITCHCOCK — REVISIONS OF NORTH AMERICAN GRASSES. 203 



Panicum amplifolium Steud. Syn. PL Glum. 1: 53. 1854. "Setaria macrostachya 

 Hochst. in Hrbr. Kappleri nr. 1411. Surinam." A fragment of this collection is in the 

 National Herbarium. 



Panicum subsphaerocarpum, Salzm.; Schlecht. Linnaea 31: 483. 1862. "Salzm. pi. 

 exsicc. 'Bahia in fruticetis. ' " Schlechtendal compares this with the preceding 

 species (P. macrostachyum), pointing out slight differences in the size of the blades. 



Chamderaphis setosa var. vulpiseta Kuntze, Rev. Gen. PL 2 :769. 1891. Based on 

 Panicum vulpisetum Lam. 



Chamaeraphis composita Kuntze; Beal, Grasses N. Amer. 2: 154. 1896. Based on 

 Setaria composita H. B. K. 



Chaetochloa composita Scribn. U. S. Dept. Agr. Div. Agrost. Bull. 4 : 39. 1897. 

 Based on Setaria composita H. B. K. 



Chaetochloa vulpiseta Hitehc. & Chase, Contr. U.S. Nat. Herb. 18:350. 1917. 

 Based on Panicum vulpisetum Lam. 



DESCRIPTION. 



Plants perennial, branching at base, often in large tufts; culms glabrous, stout, often 

 decumbent at base, as much as 2 meters tall; sheaths keeled, glabrous, or scaberulous 

 or hispidulous toward the summit or rarely all over, hispid on the margin and densely 

 hispid on the well-marked ridge of the collar, the hairs yellowish, as much as 4 mm. 

 long; ligule densely hispid like the collar, 2 mm. long; blades flat, gradually narrowed 

 from the middle toward both ends, the larger somewhat plaited, scabrous, especially 

 beneath, as much as 50 cm. long and 3 cm. wide; panicles rather densely and evenly 

 flowered, tapering toward the apex and often somewhat tapering at base, as much as 

 30 cm. long and 4 or 5 cm. wide (secondary panicles much smaller, sometimes only 

 5 cm. long), the branches stiffly ascending or spreading, as much as 2 or 3 cm. long 

 and of about equal length except toward the summit, the axis densely villous; bristles 

 1 or 2 at the base of each spikelet, slightly flexuous, brownish, antrorsely scabrous, 

 mostly 1 to 2 cm. long, appearing secund on the branches after the fall of the spikelets; 

 spikelets ovoid, 2 to 2.5 mm. long, pale, moderately turgid on the convex side; first 

 glume about half as long as the spikelet, 3-nerved; second glume two-thirds to three- 

 fourths as long as the fertile lemma, 7-nerved ; sterile lemma as long as the fertile, 

 5-nerved, the pal ea well developed; fertile lemma lanceolate, acutish, strongly and 

 rather coarsely cross-wrinkled. 



The panicles sometimes resemble those of C. magna but are less densely flowered ; the 

 fertile lemma is cross-wrinkled instead of nearly smooth. From C. macrosperma it is 

 distinguished by the smaller spikelets. 



DISTRIBUTION. 



Open ground and brushy slopes, West Indies and southern Mexico to Argentina. 



Tabasco: San Antonio, Rovirosa 254 (N. Y. Bot. Gard. Herb.). 



Guatemala: Nenton, Seler 2716. 



Honduras: San Pedro Sula, Thieme 5582, 5582B. Without locality, Thieme 5574. 



Salvador: San Salvador, Renson 296. 



Nicaragua: Jinotepe, Hitchcock 8683. 



Costa Rica: Colonia Carmona, Jimenez 368. Las Delicias del Reventazon, Pittier 

 16171. 



Panama: Puerto Obaldia, Pittier 4332. Culebra, Pittier 2121: Hitchcock 7898, 7906, 

 8026. Gorgona, Maxon 4734. Las Cascadas, Pittier 3744. Taboga Island, Hitch- 

 cock 8093. Toro Point, Hitchcock 8046. Gatiin Lake, Pittier 6850. 



Porto Rico: Jayuya, Sintenis 6335. San Juan, Chase 6371. Rio Piedras, Stevenson 

 3024. 



Trinidad: Bot. Gard. Herb. 3304; Crueger. 



Tobago: Broadway 4898. 

 168000—20 7 



