16 NORTH AMERICAN SPECIES OF LEPTOCHLOA. 



Diplachne dubia Scribn. Bull. Torr. Bot. Club. 10: 30. 1883. Transferred to 

 the genus Diplachne. 



Lept ochloa pringlei, Beal Grasses N. A. 2: 436. 1896. "D. pringlei Vasey 

 ined. Arizona, Pringle, 1884." In the Department herbarium is a specimen 

 collected by Pringle in 1884 in Tucson (No. 13), which answers to the 

 description given in Beal's Grasses, but seems to me to be a small form of 

 L. dubia. This is figured in IT. S. D. A. Div. Agrost. Bull. 7: 224, fig. 218. 



Diplachne dubia Pringleana O. K. Rev. Gen. PI. 3 2 : 348. 1898, transferred 

 to Leptochloa by Scribner and Merrill, U. S. D. A. Div. Agrost. Bull. 24: 27, 

 1901, is a robust variety from Chihuahua, Mexico (Pringle 422). 



Stems 3 to 10 dm. high from a perennial root. Leaves long and narrow, tapering to 

 a slender point as in L. fascicular is Gray, usually not over one-half cm. wide. 

 Panicle, consisting of several or many more or less spreading spikes, 5 to 15 

 cm. long. Spikelets, 5 to 10 mm. long. 5 to 8 flowered, or in the smaller forms 

 only 2-flowerecl. Empty glumes acute, upper 4 mm. long, lower a little 

 shorter and narrower; flowering glumes broad and obtuse or emarginate at 

 apex, the midrib sometimes extending into a short point. This species is 

 readily distinguished by the broad, scarious emarginate apex of the flowering 

 glumes. This is a valuable forage plant in the Southwest, where it is called 

 "sprangle." Experiments indicate that it may prove valuable under culti- 

 vation in the arid regions of our Western States. 



Distribution: Arizona: Lemmon 368. New Mexico: Wooten 418. Texas: Jones 

 4210; Wright 767. Florida: Garber 33; Curtiss 3450; Simpson 302; Tracy 6453. 

 Mexico: Palmer 270, 273, 530, 381, 482, 468: Bourgeau 533; Brandegee 6; 

 Schaffner 671, 1079, 933; Pringle 422; Xantus 119; Botteri 690. 



C— Diplachne. Spikelets several flowered, arranged more distantly on the branches of the 

 panicle and not conspicuously one-sided. 



LEPTOCHL.OA FLORIBUNDA Doell in Mart. Fl. Bras. 2 3 : 89. 1878. Type 

 locality: " ad ripas fluminis Amazonum inter Manaos et Santarem (Spruce) ."' 

 (PI. VI, fig. 1; text fig. 11.) 



Diplachne halei Nash. Bull. N. Y. Bot. Gard. 1 : 292. 1899. Type collected in 

 Louisiana by Hale. Co-type in herbarium U. S. D. A. 



Fig. 11.— L.floribunda. 



Leptochloa halei Scribn. & Merr. U. S. D. A. Div. Agrost. Bull. 24: 27. 1901. 

 Transfers Diplachne halei. The relation of L. halei to L. floribunda is dis- 

 cussed in the article last cited. Going over the same evidence I believe that 

 we are safe in making the present disposition. 



Plant with the aspect of L. fascicuJaris Gray. Panicle oblong, rather compact, 

 with numerous branches 4 to 6 cm. long. Spikelets 4 to 5 mm. long, 5 to 

 7 flowered. Empty glumes slightly unequal, upper about 2 mm., lower 

 shorter. Flowering glumes with a very short point. 



Probably introduced in the United States from farther south. 



Distribution: Texas to Brazil. Key West: Blodgett; Mississippi: Tracy 7451; 

 Louisiana: Hale; Texas: Drummond 322; Brazil: Spruce 1112. 



