4. Erianthus giganteus (Walt.) Muhl. Sugarcane plumegrass. Fig. 171. 



Perennial; culms 1-3 m. tall, appressed-villous below the panicle, the nodes 

 appressed-hispid, the hairs deciduous; sheaths and blades from nearly glabrous to 

 shaggy appressed-villous; blades 4-15 mm. broad; panicle 10-15 (-40) cm. long, 

 oblong or ovoid, tawny to purplish; spikelets 5-6 (-7) mm. long, sparsely long- 

 villous on the upper part, shorter than the copious basal hairs; awn 10-25 mm. 

 long, terete, straight or rarely slightly flexuous; rachis joint and pedicel long- 

 pilose. E. saccharoides Michx., E. Tracyi Nash, E. laxus Nash, £. compactus Nash. 



Infrequent in sandy soil, usually near moisture, often in marshes or seepage 

 areas, in Okla. {Waterfall), e. and s.e. Tex., fall; N. Y. to Tex.; Cuba; probably 

 elsewhere in trop. Am. 



58. Andropogon L. Bluestem 



In the present strict sense this is a genus of some few dozens of species of the 

 temperate and subtropical areas of the Old World and New World. 



1. Andropogon glomeratus (Walt.) B. S. P. Bushy beardgrass. 



Perennial; culms erect, 5-15 dm. tall, compressed, with broad keeled overlapping 

 lower sheaths, the flat tufts often forming dense usually glaucous clumps, the 

 culms from freely to bushy-branching toward the summit; sheaths occasionally 

 villous; blades elongate, 3-8 mm. wide; inflorescence dense, feathery, from flabel- 

 late to oblong, the paired racemes 1-3 cm. long, about equaling the slightly 

 dilated spathes, the enclosed peduncle and ultimate branchlets long-villous, the 

 peduncle at least 5 mm. long or often longer; rachis very slender, flexuous, long- 

 villous; sessile spikelets 3-4 mm. long, the awn straight, 10-15 mm. long; sterile 

 spikelet reduced to a subulate glume or wanting, the slender pedicel long-villous. 

 A. virginicus var. abbreviatus (Hack.) Fern. & Grisc. 



Frequent in moist areas, in marshes and swamps, on wet springy slopes and 

 in seepage areas, on edge of water about springs and ponds, in Okla. (Haskell 

 Co.), e. half of Tex., rare westw., in N. M. (Eddy Co.) and Ariz. (Coconino, 

 Mohave, Maricopa, Pinal and Santa Cruz cos.), late summer-fall; s.e. U.S. n. to 

 N.E., Ky., Okla.; also N.M., Ariz., Nev., Calif., Mex., W.I. and C.A. 



59. Sorghum Moench 



A large genus centered in the Near East; at least 2 species are cultivated and 

 escaped in Texas. 



1. Sorghum halepense (L.) Pers. Johnson grass. Fig. 172. 



Robust perennial; culms 5-15 dm. tall, from extensively creeping scaly rhizomes; 

 blades mostly less than 2 cm. wide; panicle open, terminal, of several to numerous 

 racemes, 15-50 cm. long; spikelets tardily disarticulating just below each sessile 

 spikelet; fertile sessile spikelet 4.5-5.5 mm. long, ovate, appressed-silky, the 

 readily deciduous awn 10-15 mm. long, geniculate, twisted below; sterile pedi- 

 cellate spikelet 5-7 mm. long, lanceolate. 



Open ground, fields and waste places, along irrigation ditches and in wet depres- 

 sions, Mass. to la. and Kan., s. to Fla. and Tex., w. to s. Calif.; nat. of the Medit. 

 region but in the trop. and warmer regions of both hemispheres. 



Cultivated for forage, but because of the diflficulty of eradication it becomes a 

 troublesome weed. 



60. Manisuris L. Joint-tail 



Perennial moderately tall plants; racemes nearly cylindrical, their rachises gla- 

 brous or nearly so and quite thick, the base of each internode on one side sculp- 

 tured with a niche into which the spikelets fit closely; pedicellate spikelets reduced, 



338 



