MANUAL OF THE GRASSES OF THE UNITED STATES 



767 



very like the primary racemes of A. 

 elliottii; spikelets 4 mm. long. % 

 — Dry sandy soil, northern Florida 

 to Louisiana. Possibly a form of A. 

 elliottii in which the enlarged sheaths 

 and cleistogamous inflorescence are 

 not developed. 



30. Andropogon campyloracheus 

 Nash. (Fig. 1169.) Culms tufted, 

 erect, 40 to 80 cm. tall, simple or 

 with a few branches about the middle; 



Figure 1169. — Andropogon campyloracheus, X 1. 

 (Combs 677, Fla.) 



sheaths and lower part of the blades 

 appressed-villous, the blades about 2 

 mm. wide; racemes 2 to 4, mostly 2, 

 on long flexuous peduncles exserted 

 from long narrow spathes, the slender 

 rachis very flexuous, the joints and 

 pedicels much longer than the sessile 

 spikelet, long-villous, the lowermost 

 rachis joint often elongate; sessile 

 spikelet 5 to 6 mm. long, slender, the 

 awn loosely twisted, mostly about 2 

 cm. long; pedicellate spikelet reduced 

 to a slender glume or obsolete. % 

 — Dry sandy pine woods, Florida, 

 Mississippi, and Louisiana. 



Section 3. Amphilophis Trin. 



Perennials, simple or sparingly branch- 

 ing; racemes several to numerous 

 in a leafless panicle, at least the 

 lower racemes short-peduncled, 

 mostly on a relatively long axis, 

 rachis straight, the joints and 

 pedicels flat, with thick bearded 

 margins, the center subhyaline. 



31. Andropogon wrightii Hack. 

 (Fig. 1170.) Plants somewhat glauc- 

 ous; culms tufted, 50 to 100 cm. tall, 

 simple, the nodes usually hispid; 

 blades flat, 3 to 5 mm. wide, tapering 

 to a fine point; racemes 3 to 7, sub- 

 erect, mostly 3 to 6 cm. long, green 

 or tawny, not conspicuously woolly, 

 the hairs of rachis joints and pedicels 

 much shorter than the spikelets; pe- 

 duncle usually long-exserted ; sessile 

 spikelet about 6 mm. long, short- 

 pilose at base, the first glume several- 

 nerved toward the summit, stiffly 

 short-ciliate on the keels above; awn 

 twisted below, geniculate, 10 to 15 

 mm. long; pedicellate spikelet about 

 as large as the sessile one, awnless. 

 % — Rocky hills and mesas, south- 

 ern New Mexico, and northern Mex- 

 ico. An occasional spikelet is found 

 with a pitted first glume. In Mexican 

 specimens the glumes are commonly 

 pitted. 



32. Andropogon perforatus Trin. 

 ex Fourn. (Fig. 1171.) Culms densely 

 tufted, geniculate at base, 50 to 100 

 cm. tall, simple or with a few leafy 

 shoots at base; nodes from obscurely 

 appressed-pubescent to densely short- 

 bearded; blades 2 to 4 mm. wide, the 

 apex attenuate; racemes few to 

 several, mostly 5 to 7 cm. long, one 

 or more of them on slender individual 

 peduncles aggregate on a short axis, 

 the common peduncle usually long- 

 exserted; margins of rachis joints and 

 pedicels densely long-villous; sessile 

 spikelet 4 to 6 mm. long, short-pilose 

 at base, the first glume sparsely 

 hairy and with a small pit like a 

 pinhole; awn twisted below, genicu- 

 late, 2 to 2.5 cm. long; pedicellate 

 spikelet reduced. % — Mesas, rocky 



