PANICE^ 91 



back, 3 mm. long, first and second glumes 5-nerved, the latter 

 vvlien mature with 2-3 transverse plications on each side, third 

 glume and palea brown. 



Mexico (Rio Blanco), Palmer 468. 



Texas to Florida and Mexico. 



17. P. setaceum Michx. Fl. Bor. Am. 1:43 (1803). P. ciliati- 

 folium Michx. Fl. Bor. 1:44 (1803). P. debile Michx. Fl. Bor. 

 Am. 1:44 (1803). 



Culms ascending, branchiiig, very slender, 50-70 cm. high„ 

 Leaves throughout, or the sheaths only, smooth, 5-15 cm. long, 

 3-5 mm. wide. Spikes mostly single, terminal, and one or more 

 exserted or included in the sheaths of the npper leaves, 5-10 cm. 

 long ; rachis flexuose, 1 mm. wide. Spikelets in two or more irreg- 

 ular rows, broad-oval, 2.2 mm. long, first glume 3-nerved, second 

 2-nerved. 



Delaware, Catiby 3576. 



East Massachusetts to Illinois and southward. 



Var. ciliatifolium (Michx.) Vasey, Contrib. IT. S. Nat. Herb. 

 3:17 (1892). P. ciUatifoUum Michx. Fl. Bor. Am. 1:44 (1803). 

 P. dasijphtjllum Ell. Bot. S. C. and Ga. 1:105 (1816). Culms 

 stouter; leaf-blades mostly longer, 1 cm. wide; spikelets crowded, 

 often appearing in more than two rows, owing to the branching of 

 the pedicels of the spikelets. 



Florida, U. S. Dept. Agricul. 3, from A. H. Cttrtiss. 



Southern States. 



18. P. Humboldtianum Fliigge, Monog. 67 (1810). 



Culms hard, not flattened in drying, exserted, branching below, 

 60-80 cm. long. Leaf-blades numerous, smooth or rough, flat, 

 acuminate, 5-12 cm. long, 1-1.5 cm. wide. Spikes 3-4, approx- 

 imate, 8-10 cm. long, rachis 1.5 mm. wide. Spikelets in jDairs, 

 4-rowed, not crowded, pubescent, oval-lanceolate, 3.3 mm. long, 

 first glume with 2 nerves on the margins very close to each other, 

 over 1 mm. long, second glume smooth, 3-nerved, third shorter, 

 oval, obtuse. 



Mexico (Rio Blanco), Palmer 286. 



Mexico to Quito. 



