748 





' 



Figure 113S. — Erianthus ravennae. Racemes, X 1. 

 (Cult.) 



MISC. PUBLICATION 200, U. S. DEPT. OF AGRICULTURE 



2 to 6, sometimes only 1, approx- 

 imate; spikelets about 5 mm. long. 

 O (Eulalia viminea (Trin.) Kuntze.) 

 — Shaded banks and roadsides, Ohio, 

 Virginia, North Carolina, Kentucky, 

 Tennessee, and Alabama. Introduced 

 from Asia. 



MlCROSTEGIUM VIMINEUM Var. 



imberbe (Nees) Honda, an awned 

 form, found in Berks County, Pa., 

 and Greenville, Va. 



153. ARTHRAXON Beauv. 



Perfect spikelets usually awned, 

 sessile, the secondary spikelet and 

 its pedicel wanting or the pedicel 

 (rarely a spikelet) developed only at 

 the lower joints of the filiform ar- 

 ticulate rachis; racemes terminating 

 the branches of a dichotomously 

 forking panicle, in appearance sub- 

 digitate or fascicled. Usually low 

 creeping grasses with broad cordate- 

 clasping blades and subflabellate pan- 

 icles. Type species, Arthraxon ciliaris 

 Beauv. Name from Greek arthron, 

 joint, and axon, axis, alluding to the 

 jointed rachis. 



1. Arthraxon hispidus (Thunb.) 

 Makino. Annual; culms slender, 

 branching, decumbent or creeping, 20 

 to 100 cm. long; sheaths hispid; 

 blades ovate to ovate-lanceolate, 2 

 to 5 cm. long, 5 to 15 mm. wide, 

 ciliate toward base; panicles of few 

 to several racemes, flabellate, con- 

 tracting toward maturity, on filiform 

 peduncles; rachis joints glabrous; 

 spikelets 4 to 5 mm. long, the strong 

 nerves aculeate-scabrous; sterile lem- 

 ma with a slender geniculate awn. 

 O — Waste ground, rare, Maryland 

 (near Washington, D. C), Missouri 

 (St. Louis), and Louisiana (Richland 

 County). A. hispidus var. crypta- 

 therus (Hack.) Honda. (Fig. 1138.) 

 Spikelets slightly smaller; awn want- 

 ing or included in the glumes. O 

 — Pastures, lawns, and open ground 

 in a few localities, Pennsylvania to 

 Florida and Tennessee; Arkansas and 

 Washington; introduced from the 

 Orient. 



Figure 1137. — Microstegiumvimineum, X 1. (Wilkins 

 3716, Term.) 



Figure 1138. — Arthraxon hispidus var. cryptatherus, 

 X 1. (Cult.) 



1. Microstegium vimineum (Trin.) 



A. Camus. (Fig. 1137.) Annual; culms 

 slender, straggling, rooting at the 

 nodes, 50 to 100 cm. long, freely 

 branching; blades lanceolate, 3 to 8 

 cm. long, 5 to 10 mm. wide; racemes 



