90 PANICACE^. 



exceeding their own length, oval, obtuse or subacute, 2.5-2.7 mm. 

 long; first and second glumes equal, 3-nerved, but little longer 

 than the floret. 



Mexico (San Luis Potosi), Pringle 3755, and farther south. 

 Alkaline meadows. 



14. P. Drummondii C. Muell. Bot. Zeit. 19:332 (1861). P. 

 lentiginosmn of Vusey's Catalogue, not Presl. 



Culms erect, slender, smooth, often branching below, 60-90 cm. 

 high. Sheaths loose; blades 1-2 cm. long, 10-13 mm. wide, one 

 margin undulate. Spikes 3-5, 2-4 cm. apart, the lowest ones 7-10 

 cm. long, the upper a little shorter, rachis subflexuose, less than 1 

 mm. wide. Spikelets in pairs, obovate-oval, minutely pubescent and 

 brown-spotted, a little over 2 mm. long. Usually with a minute 

 sterile glume on the fiat side as in Panicum. 



Texas, Nealley in 1888. 



15. P. macrophyllum H.B.K. Nov. Gen. et Sp. 1:92 (1815). 

 P. planifuUum Fourn.? Hemsl. Biol. Centr. Am. Bot. 3: 48 (1880). 



Culms 90-120 cm. high, smooth. Slieaths hispid, ciliate at 

 the tliroat; ligule very short; blades fiat, scabrid or smooth, 

 18-25 cm. long, 1-2 cm. wide, acuminate, pungent-pointed. 

 Spikes 5-8, sessile, scattered, somewhat distant, the lower 6-12 cm. 

 long, the others gradually shorter, rachis flat, 1 mm. wide. Spike- 

 lets purple, more or less in four irregular rows, crowded, elliptical, 

 obtuse, 2-2.3 mm. long, first and second glumes equal, 3-nerved. 



Mexico (San Luis Potosi), Pringle 3779. 



Low fields. 



The plants were identified by Professor Scribner; who, on 

 account of meagre descriptions, is uncertain as to the correct 

 name. Tlie type specimens were not at hand for comparison. 



16. P. plicatulum Michx. Fl. Bor. Am. 1:43 (1803). P. un- 

 didatum Poir. Lam. Encycl. 5:29 (1804). 



Culms 30-60 cm. high, simple, smooth. Leaf-blades smooth, 

 15-20 cm. long, 5-8 mm. wide. Panicle 10-13 cm. long. Spikes 

 5-7, recurved, 2-6 cm. long, the upper much the shorter, rachis 

 less than 1 mm. wide, fiexuose. Spikelets in pairs, one pair about 

 3 mm. above or below another pair, oval, obtuse, convex on the 



