HITCHCOCK AND CHASE TROPICAL NORTH AMERICAN PANICUM. 527 



Fig. 



138. — P. cJiiriquiense. 

 type specimen. 



From 



110. Panicura chiriquiense sp. nov. 



DESCRIPTION. 



Plants perennial, olivaceous; culms straggling, creeping and rooting at the lower 

 nodes, softly papillose-pilose, freely branching, the leafy fertile branches ascending, 

 20 to 30 cm. high; nodes pilose; sheaths nearly as long as the internodes or the upper 

 overlapping, softly papillose-pilose; ligule about 0.5 mm. long; blades flat, somewhat 

 spreading, 4 to 7 cm. long, 7 to 10 mm. wide, nar- 

 rowly lanceolate, unsymmetrical at base and often 

 somewhat falcate, acuminate, softly papillose- 

 villous beneath, rather sparsely pilose on the 

 upper surface ; panicles short-exserted or included 

 at base, 2.5 to 3.5 cm. long, half to two-thirds as 

 wide, the few bi-anches ascending, the axis and 

 few nearly simple branches slender, villous; spike- 

 lets short-pediceled, 2.6 to 2.8 mm. long, about 

 1.1 mm. wide, elliptical; first glume about three- 

 fourths as long as the spikelet, acute, 3-nerved, 

 villous; second glume and ^sterile lemma equal, 

 covering the fruit, the glume villous, minutely 

 apiculate, the lemma usually subindurate, smooth and shining in the two middle 

 intemerves, the midnerve suppressed or evident at the summit only, the lateral 

 internerves villous; frnit 2.1 mm. long, 1 mm. wide, minutely apiculate. 



Type in the U. S. National Herbarium, no. 725186, collected "in shade along 

 trad, hillside jungle, foothills, vicinity of El Boquete, province of Chiriquf, Panama, 



altitude 1,000 to 1,300 meters, October 4, 

 1911, " by A. S. Hitchcock (no. 8313). 



Known only from the type collec- 

 tion. This species differs from P. cor- 

 dovense in the villous foliage with 

 shorter, unsymmetrical blades, the 

 less elongate culms, and the smaller 

 spikelets. In the specimens collected 

 all the panicles are terminal on the 

 branches. Whether or not the plants 

 Fig. 139.-Distribution of F. cUrnuiense. ^^ ^n earHer season bear large panicles 



on a jjrimary culm is not known. The character of the suppressed midnerve and 

 smooth middle intemerves, rare in P. cordovense, is usual and emphazised in P. chiri- 

 quiense. Only an occasional spikelet in panicles with the usual form has undiffer- 

 entiated middle intemerves. 



MISCELLANEOUS SPECIES. 



111. Panicum obtuaum H. B. K. 



Panicum ohtxisum H. B. K. Nov. Gen. & Sp. 1: 98. 1816; Contr. U. S. Nat. Herb. 

 15: 321. 1910. 



DISTRIBUTION. 



Moist sandy or gravelly soil, southwestern United States to central Mexico. The 

 type specimen from Guanajuato. 



Sonora: Nogales to Cocospora Ranch, Griffiths 6800. 



Chihuahua: Between Casas Grandes and Sabinal, Nelson 6352. Chihuahua, 

 Pringle 476. Mifiaca, Hitchcock 7734. 



