HITCHCOCK AND CHASE GRASSES OF THE WEST INDIES. 319 



toward the summit; blades flat, 30 to 60 cm. long, commonly 2 cm. wide, the 

 margins very scabrous ; racemes 10 to 12 cm. long, numerous, aggregated in a 

 fan-shaped panicle ; spikelets 4 mm. long, 1.5 mm. wide, acuminate. 



Stream banks and swamps, southern Mexico, Trinidad (St. Joseph), and 

 Tobago to South America. Originally described from Brazil. 



52. Paspalum virgatum L. Syst. Nat.*d. 10. 2: 855. 1759. 



Paspalum leucocheilum Wright, Anal. Acad. Cienc. Habana 8: 203. 1871. 



Paspalum virgatum var. jacquinianum Fliigge, Monogr. Pasp. 190. 1810. 



A robust perennial growing in large clumps, the erect culms commonly 2 

 meters tall, the lower sheaths nodulose in drying; blades commonly 50 cm. or 

 more long, 1 to 2 cm. wide, flat, the margins very scabrous ; racemes several to 

 many, 5 to 12 cm. long, forming a panicle 20 to 40 cm. long, a tuft of long hairs 

 in the axils, the dull purplish rachises often sparsely ciliate with long hairs; 

 spikelets in pairs, crowded, grayish, becoming rusty brown at maturity, obovate, 

 3 mm. long, 2 mm. wide, silky-hairy around the margin of the glume and the 

 summit of the sterile lemma. In Porto Rico this and other species of this 

 group are called " cortedero " because of the cruel cutting edges of the blades. 



Banks and slopes, mostly moist and swampy ground, Mexico and the West 

 Indies to Argentina. Originally described from Jamaica. Paspalum leuco- 

 cheilum was described from the Isle of Pines ; P. virgatum var. jacquinianum 

 from Caribbean islands. Throughout Cuba, Jamaica, Haiti, Santo Domingo, 

 Porto Rico, Trinidad, and Tobago, and represented by specimens from Dominica, 

 Martinique, St. Lucia, Grenada, and Barbados. Called " caguazo " in Cuba. 



53. Paspalum secans sp. nov. 



Perennial, glabrous, in large clumps, with numerous long-leaved sterile 

 shoots, the strong erect simple culms commonly 1 to nearly 2 meters tall; 

 sheaths mostly overlapping, commonly separating from the culm and becoming 

 involute above, ciliate at the summit, the lower rather loose and papery; 

 ligule about 1.5 mm. long, membranaceous, with a dense row of white hairs be- 

 hind it; blades erect, as much as 1 meter long, firm, 5 to 10 mm. wide, taper- 

 ing to a base narrower than the summit of the sheath, long-acuminate, flat but 

 drying more or less involute, the margins very sharply serrulate ; racemes 5 to 

 12 (rarely as many as 20), relatively slender, sometimes flexuous, spreading, 

 6 to 15 mm. long, pilose at the base, rather remote, the panicle loose and open ; 

 spikelets glabrous, mostly pale, in pairs, not so crowded as in P. virgatum, 

 glabrous, 2.3 to 2.7 mm. long, 1.5 to 1.6 mm. wide, obovate-elliptic ; fruit about 

 2.3 mm. long, pale, minutely roughened. 



Type in the U. S. National Herbarium, no. 732740, collected on Monte Mesa, 

 Porto Rico, October 17, 1913, by Agnes Chase (no. 6174). The name refers to 

 the sharp-cutting leaf blades. 



Open slopes and dryish savannas, affecting drier situations than the other 

 allies of P. virgatum. 



Most of the Cuba and Jamaica specimens are somewhat more robust, with 

 racemes on the average more numerous (12 to 15), the spikelets slightly wider. 

 This Jamaican form, together with a yellow-panicled form of P. virgatum, Grise- 

 bach * described as P. virgatum var. stramineum, differentiating it by " axis half 

 as broad as the spikelets ; glumes straw-colored or at length purplish-tawny, 

 usually glabrous," and citing March, Jamaica, and Wullschlaegel, Antigua, and 

 also referring to Trinius, I cones, plate 131. The March specimen in the Grise- 

 bach Herbarium is the form with glabrous spikelets and pale fruit, the Wull- 

 schlaegel specimen is P. virgatum. Trinius's plate 131 shows pubescent spike- 



*FL Brit. W. Ind. 543. 1864. 

 47877°— 17 5 



