172 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE. 



times short panicle. Species probably 20, in the warmer regions; 

 10 species in the United States, mostly in the Southern and South- 

 western States. 



Type species: Cynosnrus virgatus L. 



Leptochloa Beauv., Ess. Agrost. 71, 166, pi. 15, f. 1. 1812. Beauvois includes 

 three species, Cynosnrus capiltoceus, Eleusine flliformis, and E. virgata, all of 

 which appear in the index under Leptochloa. The third species is figured and 

 hence is selected as the type. 



Diplachne Beauv., Ess. Agrost. 80, pi. 16, f. 9. 1812. The type is Festuca 

 fascicularis Lam., the only species mentioned. This is figured by Beauvois. 



Rabdochloa Beauv., Ess. Agrost. 84, pi. 17, f. 3. 1812. Beauvois includes 

 Cynosurus monostachyos, C. I'irgatus, C. domingensis, C. cruciatus, and C. 

 mucronatus, the last two with question. The species figured, C. domingensis, 

 in the explanation to the plates called Rabdochloa domingensis, is selected as 

 the type. 



Oxydenia Nutt., Gen, PI. 1: 76. 1818. Only one species included, O. at- 

 tenuata, which is Leptochloa filiformis. 



Some authors * recognize Diplachne as a distinct genus, including Leptochloa 

 fascicularis, L. floribunda, and L. dubia. In this group the spikelets are some- 

 what pediceled and are less distinctly arranged in one-sided spikes. Those 

 who recognize the genus place it in the tribe Festuceae. 



Leptochloa filiformis (Lam.) Beauv. (fig. 101) is an annual with 

 papillate-pilose sheaths, small spikelets, the awnless florets shorter 

 than the glumes, and numerous very slender spikes 3 to 6 inches long 

 arranged in a panicle as much as a foot long. This is a weed in 

 cultivated soil from Virginia to Florida and California; common 

 also in the Tropics; sometimes called red sprangle-top. 



Leptochloa fascicularis (Lam.) Gray is a smooth, erect or pros- 

 trate annual with several-flowered spikelets, the awned florets longer 

 than the glumes; found in ditches and brackish meadows from 

 Massachusetts to Florida and New Mexico. 



The other species are more local. Two perennials, L. domingensis 

 (Jacq.) Trin. and L. virgata (L.) Beauv., are tropical species which 

 reach the United States in southern Florida and southern Texas, 

 respectively. Leptochloa dubia (H. B. K.) Nees, a perennial with 

 comparatively few spikes and broad lemmas notched at the apex, the 

 nerves glabrous (the margin pubescent), is found in Florida and 

 from Texas to New Mexico. In the Southwest it is called sprangle 

 or sprangle-top and Texas crowfoot, and it is important as a forage 

 grass. 



For a revision of the species of Leptochloa found in the United 

 States, see Hitchcock, U. S. Dept. Agr., Bur. PL Ind. Bull. 33. 1903. 



S3. TRIPOGOX Roth. 



Spikelets several-flowered, nearly sessile, and appressed in two rows 

 along one side of a slender rachis, the rachilla disarticulating above 

 the glumes and bet\veen the florets; glumes somewhat unequal, 

 acute or acuminate, narrow, 1 -nerved; lemmas narrow. 3-nerved, 



1 Nash in Small, Fl. Southeast. U. S. 145, 1900 ; in Britt. and Brown, Illustr. FL, ed. 2, 

 1:236. 1913. 



