432 POACE^. 



rachis in 2 irregular rows. Second empty glume 1- 



nerved (d) 



d. Panicle spikelike 5 



d. Panicle branching (e) 



e. Floral glume less than 3 mm. long (m) 



m. Panicle 2-8 cm. long 6 



m. 15-25 cm. long 7 



e. Floral glume 3 mm. long, 8 



e. Floral glume 3.5 mm. long 9 



e. Floral glume 4 mm. long (n) 



n. Second empty glume 3 mm. long 10 



n. Second empty glume 4-5 mm. long 11 



0. Gouinia Fourn. as a genus. Spikes of the panicle long 

 and slender. Spikelets scattered along the three sides of 



the rachis, 1-nerved, floral glume 3-nerved (o) 



o. Awn 1-3 mm. long ■ 13 



0. Awn 8-12 mm. long 13 



1. L. scabra Xees, Agrost. Bras. 435 (1829). L. Langloisii 

 Vasey, Bull Torr. Club, 12:7(1885). L. Ludoviciana Yiisey. 



Culm smooth, stout, leafy, 100-130 cm. high. The lower 

 blades one-third as long as the culm ; sheaths loose, compressed., 

 glaucous, 30 cm. long, about 1 cm. wide. Panicle scarcely protrud- 

 ing or partially included by the upper leaf, racemose, 20-30 cm. 

 long, about 5 cm. wide, loose, simple, spikes 100 or more, crowded 

 below, single or 2-3 together, 5-7 cm. long. Spikelets 3-4-flowered, 

 sessile, loosely imbricate, 4 mm. long; the internode of the rachilla 

 for each floret 1 mm. long; empty glumes membranous, ovate, 

 acute, 1-nerved, first 0.7 mm. long, second a third longer; floral 

 glume oval when spread, mucronate, 3-nerved, hairy on the back, 

 2.5 mm. long; palea about as long as its glume, ciliate on tlie 

 nerves, 2-toothed. Grain 3-sided. 



Louisiana, Langlois. 



2. L. mucronata (Michx.) Kunth, Gram. 1:91 (1829-35). 

 Eleusine mucronata Michx. Fl. Bor. Am. 1:65 (1803). L. fili- 

 formis J. & C. Presl, Eel. Hsenk. 1:288 (1830). L. attenuata 

 Steud. Syn. PI. Gram. 209 (1855). L. pelhicida 1. c. 



