350 CONTRIBUTIONS FEOM THE NATIONAL HERBARIUM. 



Tufted, erect, commonly 1 meter tall, the culms and sheaths compressed, the 

 numerous elongate blades mostly 0.8 to 1.2 cm. wide, usually reaching beyond 

 the base of the rather loose panicle of large globose spikelets and long flexuous 

 bristles. 



Savannas, rocky banks, and open woods, West Indies to Uruguay. Originally 

 described from Montevideo. Panicum onurus was first mentioned by Nees 1 as a 

 synonym under P. setosum var. "(P. onurus, Willd. Herb. — ex Humboldtianis)". 

 Nees gives as the "habitat" of /3 the following : "in regno Mexicano (ab Humb. — 

 Vidi in Herb. Willd. In Monte Video. (Sellow.) (Vidi in Herb. Reg. Berol.)" 

 The Willdenow specimen is Chaetochloa setosa, but the Sell ow specimen belongs 

 to the species later described by Trinius as Panicum onurus. Although Trinius, 

 in the work cited above, credits the name to Willdenow ("Panicum onurus 

 Willd. hb."), he describes the Sellow specimen instead of the Willdenow speci- 

 men. The name Panicum onurus was first technically published by Trinius. 

 We take the Sellow specimen from Montevideo as the type, this being the one 

 described, rather than the Willdenow specimen which Trinius did not see, 

 though, following Nees, he supposed the two specimens to belong to the same 

 species. 



Cuba, Jamaica, and Barbados. 



7. Chaetochloa impressa (Nees). 



Panicum impressum Nees, Agrost. Bras. 247. 1829. 



Panicum sphaerocarpum Salzm. ; Steud. Syn. PI. Glum. 1: 51. 1854, not Ell. 

 1816. 



Panicum ampMbolum Steud. Syn. PI. Glum. 1: 51. 1854. 



Setaria biconvexa Griseb. Fl. Brit. W. Ind. 555. 1864. 



Chaetochloa salzmanniana Hitchc. Contr. U. S. Nat. Herb. 17: 265. 1913. 



Similar to the preceding, the culms taller, less compressed, the blades broader, 

 the panicle branches 2 to 3 cm. long, at maturity ascending at a uniform angle, 

 the spikelets mostly along the lower side. 



Copses and dry open woods, southern Mexico to western Trinidad and Brazil. 

 Originally described from the Province of Bahia, Brazil. The type of Panicum 

 sphaerocarpum Salzm. and Chaetochloa salzmanniana and the type of Panicum 

 amphibolum come from Bahia. Setaria biconvexa was described from Trinidad. 



8. Chaetochloa vulpiseta (Lam.). 



Panicum vulpisetum Lam. Encycl. 4: 735 (err. typ. 745). 1798. 

 Setaria vulpiseta Roem. & Schult. Syst. Veg. 2: 495. 1817. 

 Panicum amplifolium Steud. Syn. PI. Glum. 1: 53. 1854. 





In large clumps about 1 meter -tallf the culms strongly compressed, the nu- 

 merous thin blades commonly 50 cm. long and 3 cm. wide, tapering into a 

 long petiole-like base, the bristly spikelike panicle 20 to 30 cm. long, about 

 2.5 cm. thick, tapering to both ends. 



Copses and brushy slopes, West Indies and Central America to Paraguay. 

 Originally described from Santo Domingo. Panicum amplifolium is based 

 upon Keppler 1411 from Surinam. Lamarck, Grisebach, and others cite a 

 plate in Sloane,* which, however, represents Imperata contracta (H. B. K.) 

 Hitchc. (/. caudata Trim). 



Porto Rico (between Rio Piedras and Trujillo Alto), Trinidad, and Tobago. 



9. Chaetochloa geniculata (Lam.) Millsp. & Chase, Field Mus. Bot. 3: 37. 1903. 

 Panicum geniculatum Lam. Encycl. 4: 727 (err. typ. 737). 1798. 

 Setaria geniculata Beauv. Ess. Agrost. 51, 178. 1812. 



1 See note under Chaetochloa setosa, p. 349 of the present article. 

 *Voy. Jam. 1: pi. 70. f. 1. 1707. 



