26 



State of Jalisco, 2586 J. N. Eose, August 25, 1897; Saltillo, State <.f Coaliuila, 405 

 E. Palmer, September, 1898; near Pachico, State of Chihuahua, 6246 E. W. Nel- 

 son, August 22-24, 1899. 



Bouteloua oligostachya Torr. in A. Gray, Man. Bot. ed. 2, 553 (1856). 



Durango, State of Durango, 545 E. Palmer, August, 1896; Saltillo, State of Coahuila, 

 399, 403, 406 E. Palmer, September, 1898; near Casas Grandes, State of Chihuahua, 

 6327 E. W. Nelson, August 30, 1899. 



Bouteloua polystachya Torr. Pac. R. R. Rept. 5^: 366, t. 10 (1847). 



San Antonio Valley, State of Oaxaca, 957 C. L. Smith, September 1, 1894; Durango, 

 State of Durango, 714 E. Palmer, September, 1896; Torreon, State of Coahuila, 

 514 E. Palmer, October, 1898; Saltillo, 401 E. Palmer, September, 1898. 



Bouteloua ramosa Scribn. in Vasey, IT. S. Dept. Agr. Div. Bot. Bui. 121; 44, pi. 44 

 (1891). 



Saltillo, State of Coahuila, 404 E. Palmer, September, 1898, in close tufts in low places 

 on the mesa. « 



BOUTEIiOUA REPENS (H.B. K.) Scribn. & Merrill, n. comb. {Dinebra repens 

 H. B. K. Nov. Gen. et Sp. PI. 1: 172, t.53 (1815).) 



Durango, State of Durango, 547 E. Palmer, August, 1896. 



Bouteloua tenuis Griseb. in Goett. Abh. 24: 303 (1879). 



Durango, State of Durango, 712 E. Palmer, September, 1896; Saltillo, State of Coa- 

 huila, 397, 378 E. Palmer, September, 1898; Pedrigal, Valley of Mexico, Federal 

 District, 6450 C. G. Pringle, August 20, 1896. This grass grows so abundantly 

 on the mesquite plains that it gives them the appearance of a lawn. 



Bouteloua trifida Thurb. Proc. Am. Acad. 18: 177 (1883). 



Saltillo, State of C<jahuila, 402 E. Palmer, September, 1898. 



Pentarrhaphis fournierana Hack. & Scribn. Bui. Torr. Bot. Club, 17: 232, pi. 

 107 (1890). 



Durango, State of Durango, 382 E. Palmer, July, 1896; between Acaponeta and 

 Rosario, J. N. Rose, no number, July 6, 1897; between Rosario and Colomas, 

 State of Sinaloa, 1621 J. N. Rose, July 12, 1897; near Tequila, State of Jalisco, 

 4775 Rose and Hough, July 5-6, 1899. 



Eleusine indica Gaertn. Fruct. et Sem. 1: 8 (1788). 



Coatzacoalcos, isthmus of Tehuantept^c, State of Vera Cruz, 1050 C. L. Smith, March 

 16, 1895. 



Dactyloctenium aegyptium (L.) Willd. Enum. 1029 (1809). {Cy7iosurus xgyptms 

 L. Sp. PL 72 (1753).) 



Durango, State of Durango, 735 E. Palmer, September, 1896; between Rosario and 

 Acaponeta, State of Sinaloa, 1877 J. N. Rose, July 25, 1897; Coatzacoalcos, 

 isthmus of Tehuantepec, State of Vera Cruz, 1055 C. L. Smith, February 1, 1895; 

 Colima, 10, 11, 167, 168 E. Palmer, July, 1897; Topolobampo, State of Sinaloa, 

 246 E. Palmer, September, 1897. 



LEPTOCHLOA AQTJATICA Scribn. & Merrill, sp. nov. 



An erect, glabrous, branching i)erennial about 7 dm. high, with smooth culms, flat 

 leaves, and obtuse flowering glumes. Culms much l)ranched below, striate, 

 cylindrical, rooting at the lower nodes; nodes brown, smooth; sheaths loose, 

 longer than the internodes, the lower ones compressed, smooth or minutely 

 roughened; ligule 1 to 2 mm. long, flm1)riate; leaf-l)lades thin, linear-lanceolate, 

 10 to 20 cm. long, 5 to 8 mm. wide, slightly sca])rous or nearly smooth on ])oth 

 sides, scabrous on the margins. Panicles 10 to 12 em. long, green; common 

 axis smooth or slightly roughened above, striate; branches erect, 2 to 5 cm. 

 long, alternate, scaljrous, floriferous throughout. Spikelets ovate-lanceolate, 

 rather loosely 3 to 4 flowered, about 5 mm. long, on T-hort scabrous pedicels 

 about 1 mm. in length; empty glumes very unequal, 1-nerved, slightly scabrous 

 on the keels, the first about 1 mm. long, narrowly triangular-lanceolate, acute, 



