498 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Porto Rico: Between Aibonito and Cayey, Chase 6341, Heller 522. Arecibo, 
Chase 6440. Sierra Luquillo, Hioram 368, Chase 6713. Adjuntas Road, 
Heller in 1902. Catafio, Heller 1378. Utuado, Britton & Cowell 394. Maya- 
guez, Chase 6155, 6185, Sintenis 360. Along Rio Coamo, Chase 6549. Tru- 
jillo Alto, Chase 6363, 6775. Jajome Alto, Chase 6753. Santurce, Chase 
6354. Mount Morales, Britton & Marble 1068. Fajardo, Sintenis 1254. 
DanisH West INnprEs: St. Thomas, Hggers 874 (K. U. Herb.). 
Leewarp Istanps: Antigua, Wullschlaegel 623. Guadeloupe, Duss 3179. 
Dominica, Jones 21, 25. 
Wiypwarp Is.anps: Martinique, Duss 535, 716 (K. U. Herb.). Barbados, Dash 
450. St. Lucia, Voyage of the Albatross in 1887-88. Grenada, Broadway 1870, 
3712, 4668. 
Trintpap: Port of Spain, Hitchcock 9984. Piarco Savanna, Hitchcock 103438, 
10351, 10361. Brighton, Hitchcock 10098. Pitch Lake, MMitcheock 10091. 
Cumuto Station, Hitchcock 10068. Cedros, Hitchcock 10149, Bot. Gard. Herb. 
2177, 2289. 
Tosaco: Center of island, Hitchcock 10272. Spey Side, Hitchcock 10245, 
Venezueta: Llanos del Alto Apure, Jahn 201. 
Coromaia: Cérdoba, Pittier 521, 553. Calf, Pittier 665. Santa Marta, Smith 
202, 204. 
55. Panicum stevensianum sp. nov. 
DESCRIPTION. 
Plants perennial, tufted, glabrous throughout; culms compressed, 30 to 60 cm. long, 
spreading, prostrate, rooting at the nodes, the flowering ends and the branches ascend- 
ing; sheaths loose, much shorter than the internodes, compressed, 
keeled, ciliate on the overlapping margin; ligule a delicate mem- 
brane about 0.5 mm. long; blades flat, rather firm, more or less spread- 
ing, 4 to 10cm. long, 5 to 10 mm, wide, tapering from a little above 
the sparsely ciliate, truncate-cordate base to an acuminate apex; 
panicles terminal on the culm and branches, short-exserted, 6 to 
10 cm, long, narrow, consisting of several appressed or ascending 
spikelike branches along an angled axis, the lower branches some- 
Fig, 76.—P. sle- what remote, 1.5 to 3 em. long, usually longer than the internodes, 
vensianum. 
From type 
specimen. 
the upper approximate, all spikelet-bearing to the base, the short- 
pediceled spikelets in crowded clusters, not secund, along a slender 
scabrous rachis; spikelets about 2 mm. long and 0.8mm. wide, acute, 
somewhat inflated and gaping; first glume about one-fourth the length of the spikelet, 
subacute, 3-nerved; second glume and sterile lemma equal, pointed, slightly exceed- 
ing the fruit, 3 to 5-nerved, the lemma 
inclosing a large palea and abortive 
perfect flower; fruit 1.9 mm. long, 0.6 
mm. wide, minutely scabrous at the 
acute apex. 
Type in the U.S. National Herbar- 
ium, no. 693323, collected ‘‘on wet 
sand around pool, forming a dense car- 
pet, white sand region, Campo Alegre 
near Laguna del Tortuguero,’ Porto 
Rico, November 25, 1913, by Agnes 
Chase (no. 6616). 
Fia. 77.—Distribution of P. stevensianum. 
This species appears to be most nearly related to the South American P. milioides 
Nees, from which it differs in the short erect panicle branches, spikelet-bearing to 
the base. 
