Part 3, 1915] POACEAE 



239 



exserted, 4—8 cm. long, the few subracemose branches finally somewhat spreading, pubescent 



at the base, bearing short, appressed, approximate branchlets of crowded spikelets along the 



upper two thirds to three fourths of their length; spikelets 1.8 mm. long, 0.9 mm. wide; first 



glume scarcely one fifth the length of the spikelet; second glume slightly longer than the sterile 



lemma, both 5-nerved; fruit 1.5 mm. long, 0.8 mm. wide, oval, the lemma sparsely clothed with 



appressed, silky hairs, the palea glabrous. 



Type locality: Mexico. 



Distribution : Central and southern Mexico. 



Illustration: Contr. U. S. Nat. Herb. IS: /. 119. 



80. Panicum Schiffneri Hack. Ergebn. Bot. Exp. Akad. 



Siidbras. Gram. 11. 1906. 



Plants perennial, with a long branching decumbent base, rooting at the nodes; culms strag- 

 Hng, ascending, 2-3 meters long, slender, more or less compressed, smooth or hirsute or rough- 

 ened below the nodes, producing long divaricate branches; leaf -sheaths papillose-hispid es- 

 pecially toward the summit, sometimes glabrate below, densely pubescent at the juncture with 

 the blade; ligule membranaceous-ciliate, about 0.5 mm. long; blades flat, rather firm, usually 

 horizontally spreading, 10-15 cm. long, 1.2-2.5 cm. wide (rarely larger), narrowed to the 

 usually asymmetric base, gradually tapering from below the middle to an acuminate apex, 

 scabrous and sometimes sparsely hispid on the upper surface, pubescent above the ligule, 

 scaberulous or puberulent beneath, sometimes sparsely hispid, especially along the midnerve, 

 the fine white margin undulate, scabrous; panicles 10-15 cm. long, usually about as wide, the 

 few slender scabrous branches remote, pilose in the axils, the lower branches solitary or in pairs, 

 widely spreading or reflexed, more than half as long as the very scabrous main axis, naked at 

 the base, the upper branches much shorter, ascending, the rather densely flowered short branch- 

 lets appressed along the upper half or two thirds of the branches, the bract at the base of the 

 inflorescence usually w v ell developed; spikelets short-pediceled, aggregate, scarcely 2 mm. 

 long, 1 mm. wide, turgid, glabrous; first glume less than one fourth as long as the spikelet; 

 second glume and sterile lemma equal, exceeding the fruit, obscurely nerved; fruit about 1.5 

 mm. long, 0.9 mm. wide, elliptic, sparsely covered with long, appressed, silky hairs. 



Type locality: Southern Brazil. 



Distribution: Southern Mexico and Porto Rico to Brazil. 



Illustration: Contr. U. S. Nat. Herb. 17: /. 87. 



81. Panicum parviglume Hack. Oesterr. Bot. Zeits. 51: 429. 1901. 



? Panicum conchatum Fourn. Mex. PL Gram. 25. 1886. 



? Panicum Arundinariae Trin.; Fourn. Mex. PL Gram. 25. 1886. 



Culms slender, erect, from an ascending base, 100 cm. high, striate, sparsely papillose- 

 pilose; leaf -sheaths exceeding the internodes, ciliate, sparsely papillose-pilose, striate, more 

 densely pubescent at the juncture with the blade; ligule very short, ciliate; blades lanceolate 

 or linear-lanceolate, 8-16 cm. long, 12-25 mm. wide, flat, firm, rounded at base, acuminate, 

 sparsely hispidulous, especially above, the margin very scabrous; panicles ovate, 15-25 cm. 

 long, the branches spreading or ascending, the lower distant, solitary, 10-12 cm. long, 

 the lower fourth naked, bearded at base; branchlets appressed, the longer 1-2 cm. long, 

 bearing 3-8 subcontiguous spikelets on slender, flexuous, scabrous pedicels 0.5-2 mm. long; 

 spikelets oval, 2 mm. long, 1.2 mm. wide; first glume about one fifth the length of the spikelet; 

 second glume and sterile lemma equal, slightly exceeding the fruit, faintly 5-nerved, minutely 



apiculate; fruit smooth. 



Type locality: Near San Jose, Costa Rica. 

 Distribution: Southern Mexico to Costa Rica. 

 Illustration: Contr. U. S. Nat. Herb. 15: /. 120. 



82. Panicum verrucosum Muhl. Descr. Gram. 113. 1817. 



Panicum debile Ell. Bot. S. C. & Ga. 1: 129. 1816. Not P. debile Desf. 1798. 

 Panicum umbraculum Bosc; Spreng. Syst. 1: 314, as synonym. 1825. 

 Panicum rugosum Bosc; Spreng. Syst. 1: 314, as synonym. 1825. 



Plants bright-green, solitary or few together, lax, at first erect but soon decumbent at 

 base, and ascending or widely spreading; culms slender, 20-150 cm. high; leaf-sheaths 



