494 



CONTRIBUTIONS FEOM THE NATIONAL HERBARIUM, 



Pig. 69.— Distribution of P. polygonaium. 



Costa Rica: Boraca, Tonduz 44G0. Puerto Limon, Ilitehcock 8421. Llano 

 Grande de Puriscal, Jimenez 881. Hacienda de Guacimo, Tonduz 27. San 

 Jose, Pitiier 1183. Echeverria, Pittier & Tonduz 2479. Carrillo, Biolley 

 3107, Pittier 1182. Talamanca, Tonduz 8557. River Torres, San Francisco, 



Jimenez 126. Tuis, Tonduz 11396. 

 Tnrrialba, Tonduz 4092, 8244. 

 Buenos Aires, Tonduz 4042. Rio 

 Tuis, Tonduz 8187. Boca Zhor- 

 quin, Tonduz 8557. Quebrada de 

 Tocori, Tonduz 7542. Santo Do- 

 mingo de Golfo Dulce, Tonduz 

 10099. Piedra del Convento, Pit- 

 tier 3650. 

 Panama: Boca del Toro, Hart 73. 

 Mount Hope, Hitchcock 9172. Be- 

 tween Mindi and Colon, Hitchcock 

 7943. Between Bohlo and Frijoles, Hitchcock 8395. Gorgona, Amer. Chr. 

 Nat. Herb. 58. 

 Thinidad: Arima, Hitchcock 10297, 10306. Cumuto Station, Hitchcock 10077. 

 Port of Spain, Hitchcock 9953. Tabaquite, Hitchcock 10132. Caparo, Broad- 

 way 2837. 

 Tobago: Mason Hall, Broadway 4:4!1%. 

 Colombia: Santa Marta, Smith 206, 2190, 2747. 



51. Panicum irn'll eflorum sp. nov. 

 description. 



Plants perennial; culms ascending or erect from an elongated creeping base, rooting 

 at the nodes, glabrous, 0.8 to 2 meters liigb, 4 to 5 mm. thick, compressed, the nodes 

 pubescent or glabrous, usually with one to several long erect panicle-beai'ing branches; 

 sheaths about as long as the internodes, keeled toward the summit, ciliate on the 

 margin and puberulent at the junction with the blade, otherwise glabrous or sparsely 

 papillose-hispid; ligule wanting, the ligular region puberulent; blades fiat, 20 to 40 cm. 

 long, 1 to 2 cm. wide, rarely wider, long-acuminate, somewhat na^rrowed to the sub- 

 cordate base, glabrous or very sparsely hirsute, the margin scabrous; panicles 20 to 35 

 cm. long, about 6 cm. wide, in outline tapering to both ends, consisting 

 of numerous ascending or spreading, often curving, slender spikelike 

 branches, solitary or in fascicles along an elongated glabrous axis, the 

 lower distant, the upper approximate, the scabrous-angled, often 

 sparsely pilose rachises bearing throughout their length along their 

 lower side evenly disposed short approximate densely flowered branch- 

 lets, those of the lower branches sometimes as much as 15 mm . long, the 

 others 1 or 2 mm. long; spikelets subsessile, 1.3 mm. long, about 0.5 mm. 

 wide, glabrous, the first glume about one-third the length of the spikelet, 

 the second glume and sterile lemma equal, the lemma inflated boat- 

 shaped with a lajge membranaceous palea; fruit 1.2 mm. long, 0.4 mm. wide, acute, 

 the lemma boat-shaped. 



Type in the U. S. National Herbarium, no. 693327, collected in water of swamp, 

 Frijoles, Canal Zone, Panama, October 12, 1911, by A. S. Hitchcock (no. 8387). 



This species differs from Panicum pilosum in its larger size, its strong decumbent 

 rooting base, and its longer blades and panicles. It appears to be the same as Panicum 

 distichum landfolium Griseb.^ which was previously included^ under P. pilosum. 



Fig. 70. — p. 

 millefloTum. 

 From type 

 specimen. 



1 Fl. Brit. W. Ind. 548. 1864. 



2 Contr. U. S. Nat. Herb. 15: 114. 1910. 



