HITCHCOCK AND CHASE NORTH AMERICAN PANICUM. 



77 



upper blades, 20 to 30 cm. long, usually less than half as wide, the branches ascending, 

 naked at the base, the branchlets more or less appressed, bearing short-pediceled, 

 approximate, but not crowded spikelets 3 mm. long, 1 mm. wide; first glume half to 

 two-thirds the length of the spikelet, acute, 3 to 5-nerved; second glume and sterile 

 lemma strongly 7 to 9-nerved; fruit 1.9 to 2 mm. long, 0.9 mm. wide, elliptic. 



This species differs from P. diffusum in its robust habit, wider, flat blades, hirsute 

 on both surfaces, and in its larger spikelets. 



DISTRIBUTION. 



Low moist ground, Mexico, Central America, and the West Indies; also in Ecuador.. 

 Mexico: Borrego pres Orizaba, Bourgeau 2751; Yucatan, Izamal, Gaumer 2477. 

 Costa Rica: Salinas Bay, Pittier & Durand 2633. 

 Cuba: Santiago de las Vegas, Tracy 9116; Herradura, Tracy 9068; La Soledad, 



Eggers 5406; Calvario, Leon 922; Guayabal, Leon 922b; Without locality, 



Wright 758. 

 Porto Rico: Tabucoa, Sintenis 4983. 

 Leeward Islands: Guadeloupe, Duss 3184 and a specimen without number or 



date. 

 Ecuador: Manabi, Eggers 15419. 



38. Panicum hirsutum Swartz. 



Panicum hirsuium Swartz, Fl. Ind. Occ. 1: 173. 1797. "Habitat in Jamaicae et 

 Hispaniolae graminosis." The type, in the Swartz Herbarium, is from "Jamaica, 

 Swartz." 



description. 



Plants robust, culms as much as 1 cm. thick and 1.5 meters or more high, simple or 

 sparingly branching, glabrous or with a few scattered hairs, the nodes appressed- 

 pubescent; sheaths mostly overlapping, appressed papil- 

 lose hirsute, the hairs sometimes dense at the summit; 

 ligules dense, about 3 mm. long; blades flat, 20 to 50 cm. 

 long, 20 to 35 mm. wide, scarcely narrowed to the rounded 

 base, glabrous or with a few hairs toward the base, the 

 margin serrulate; panicles short-exserted or included at 

 base, 20 to 35 cm. long, 3 to 12 mm. wide, compact, 

 densely flowered, the long lower branches erect, naked 

 at base; spikelets 2 to 2.2 mm. long, about 0.9 mm. wide, 

 rather turgid, abruptly pointed; first glume scarcely half 

 the length of the spikelet, acute, 3 to 5-nerved; second 

 glume and sterile lemma 5 to 7-nerved; fruit 1.5 mm. long, 0.7 mm. wide, elliptic. 



This species is much more robust than any other in this group, to which, because 

 of its compact panicle, it is not very closely allied. 



Fig. 66.— P. hirsutum. From 

 type specimen. 



distribution. 



Gravelly river banks and wet places, Mexico, Central America, and the West Indies. 

 Leeward Islands: Guadeloupe, Duss 3917. 

 Mexico: Oaxaca, Pringle 5573. 

 Costa Rica: Confluence of Puerto Viejo and Sarapiqui, Biolley 7467; PortLimon, 



Pittier in 1904. 

 Trinidad: Botanic Gardens Herb. 2295, Broadway 2629. 



