10 NORTH AMERICAN SPECIES OF LEPTOCHLOA. 



4. Flowering glume broad, truncate and more or less emarginate; sometimes 

 slightly awned from the protrusion of the mid-nerve dubia. 



4. Flowering glume rounded at apex and short-awned or mucronate 5 



5. Panicle 2 to 3 inches long. Plant with numerous culms, a few inches to a foot 



high; leaves 3 or 4 inches long viscida. 



5. Panicle larger, culms 2 to 3 feet tall, leaves a foot or more long__ floribunda. 



6. Flowering glume awned fascicularis. 



6. Flowering glume awnless or mucronate imbricata. 



7. Spikelets usually 2-flowered, sometimes 3 or even 4 flowered, 1 to 2 mm. long, 



branches of panicle very slender, upper empty glume as long as or longer 

 than the first flowering glume, latter obtuse mucronata. 



7. Spikelets usually 3 to 4 flowered, rather closely imbricated, spikes shorter and 



close set on the axis, forming a narrow panicle; empty glumes shorter than 

 the first flowering glume 8 



8. Sheaths scabrous, glumes sharp-pointed scabra. 



8. Sheaths smooth; flowering glumes rounded or truncate at apex 9 



9. Sheath ciliate on margin above; flowering glume more or less awned. 



domingensis. 

 9. Sheath not ciliate ; flowering glume awnless nealleyi. 



HISTORY OF GENUS. 



The genus Leptochloa was established by Palisot de Beauvois. a To 

 his new genus he refers Cynosurus capillaceus, Eleusine filiformis, 

 and E. virgata. The last of these species is figured 6 and in the 

 description c of plates he uses the name Leptochloa virgata. It may 

 be inferred that he intends to make the new combination for the 

 other two species, as in the index, page 166, he indents under Lep- 

 tochloa the three names, capillacea, filiformis, and virgata. It may 

 be remarked that if one intends to be very accurate in regard to cita- 

 tions these three species of Leptochloa should be referred to page 166 

 (the index) rather than page 71 in the body of the work, where the 

 genus is described. The same remark would apply to the most of 

 Beauvois's species. 



Beauvois also established the genera Diplachne, d to which he refers 

 Festuca fascicularis Lam., and Rabdochloa, 6 to which he refers Cyno- 

 surus monostachyos, virgatus, domingensis, cruciatus? , mucronatus? . 



Kuntze substitutes Rabdochloa for Leptochloa because Beauvois 

 assigns five species to the former and only three to the latter. 



Professor Scribner unites these under the genus Leptochloa/ Pro- 

 fessor Gray also placed Diplachne under Leptochloa as a section.! 7 

 Nuttall A proposed the genus Oxyden ia to include O. attenuata (Eleusine 

 mucronata ) . 



I have accepted the genus as delimited by Scribner, U. S. D. A. Div. 

 Agros. Bui. 20:110. Our species all are annuals except L. dubia. 



«Essai d'une nouvelle Agrostographie, 71. 1812. e 1. c. p. 84. 



61. c, Atlas, pi. xv, fig. 1. /Proc. Acad. Phil., 1891: 303. 



c 1. c. , Atlas, 10. g Man. , Ed. I. 588. 



d l. c.,80. h Gen. 1:76, 1818. 



