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



on slender branchlets borne in the axils of the broad spathelike 

 sheaths of the main culm; secondary inflorescence of numerous pairs 

 of racemes on short peduncles subtended by broad spathes, these on 

 short bearded often fascicled branchlets borne in the axils of the 

 spathelike sheaths of the main culm and short primary branches, 

 the whole forming a series of flabellate tufts with conspicuous purplish 

 to copper-brown spathes, 5 to 10 mm wide, much exceeding the 

 feathery racemes ; racemes flexuous, 3 to 4 rarely to 5 cm long, the 

 slender rachis joints and pedicels 

 long- villous ; sessile spikelets 4 to 5 

 mm long, those of the late enclosed 

 racemes cleistogamous, the awn 

 loosely twisted, 10 to 15 mm long; 

 pedicellate spikelets obsolete or 

 nearly so. % — Open ground, old 

 fields, and open woods, mostly in 

 the Coastal Plain, New Jersey to 

 Florida and Texas, north to south- 

 ern Missouri, Indiana, and Tennes- 

 see (fig. 1656). The flattened ferru- 

 gineous upper sheaths are conspic- 

 uous in winter. The characteristic 



Figure 1656.— Distribution of 

 Andropogon elliottii. 



plant is very striking, but occa- 

 sional individuals occur with less 

 aggregate upper sheaths, and others 

 with scarcely dilated sheaths, 

 aggregate or scarcely aggregate. 

 This form, which has been distin- 

 guished as A elliottii var. gracilior 

 Hack., appears to verge into A. 

 subtenuis Nash. 



26. Andropogon subtenuis Nash. 

 (Fig. 1657.) Culms in small tufts, 

 slender, erect, 40 to 70 cm tall, the 

 upper third sparingly branching; 

 foliage glabrous or nearly so, the 

 blades 1.5 to 2 mm wide; inflores- 

 cence narrow, of few to several pairs of racemes on elongate filiform 

 peduncles short-exserted from near the summit of the elongate slender 

 spa the, the ultimate branches sometimes long- villous toward the sum- 

 mit; racemes 2, flexuous, 2 to 3 cm long, very like the primary racemes 

 of A. elliottii; spikelets 4 mm long. % — Dry sandy soil, northern 

 Florida to Mississippi. Possibly a form of A. elliottii in which the 

 enlarged sheaths and cleistogamous inflorescence are not developed. 



27. Andropogon campyloracheus Nash. (Fig. 1658.) Culms 

 tufted, erect, 40 to 80 cm tall ; simple or with a few branches about 



Figure 1657.— Andropogon subtenuis, X 1. 

 (Tracy 4701, Miss.) 



