582 GKAMiNi:.'E. (C.llASS FAMILY.) 



3-4), cxscrtcd, or included in the upper sheaths ; awn 3-4 times the length of 

 the ghiincs ; hairs of tlic very slender rachis long and glossy. (A. argentcus, 

 Ell., not of DC.) — Wet or dry jjinc barrens, Floiida to North Carolina. ScpL 

 and Oet. — Somewhat variable, but distinguished by the dilated clustered sheaths, 

 and by the silvery hairs of the spikes. 



8. A. VirginicUS, L. Culms mostly tall, erect or bending, with the joints 

 remote and bearded ; branches 1-2 from the upper dilated sheatiis, compound 

 and forming a long and loose panicle; spikes by pairs (rarely by fours), shorter 

 than the sheaths ; awn straight, four times the length of the glumes ; sterile flower 

 none. (A. vaginatus, Ell., the short branches or peduncles incluiled in the more 

 inflated slieaths. A. dissitiflorus, Micfix. 1 A. gracilis, Carpenter, the spikes 

 borne at the summit of elongated simple branches) — Barren soil, Florida to 

 Mississippi, and northward. Sept. and Oct. 



9. A. macroUl'US, Michx. Spikes by pairs, exceedingly numerous, crowd- 

 ed in a large and close panicle ; awns 3-4 times the length of the glumes ; sterile 

 flower an awn-like glume. — Varies with the whole plant glaucous and more 

 slender, branches and spikes more scattered. — Low barren soils, Florida, and 

 northward. Sept. — Culms 2° - 5° high. 



10. A. ternarius, Michx. "Branches remote, alternate, solitary, simple, 

 bearing mostly three distant alternate 2-clcft spikes ; hairs of the involucre shorter 

 tlian the glume; flowers 3-androus; palea; somewhat villous; awn long, con- 

 torted." Michx. In Carolina. ( « ) 



§ 2. IIETEKOPOGON. — Upper Jlower staminate or pistillate. 



11. A. melanoearpus, Ell. Culms tall (4°-8° high) panicled above; 

 leaves elongated ; spikes lumierous, approximate, 1 -sided, shorter than their 

 slender filiform-pointed sheaths ; spikelets large, the two lowest pairs glume-like, 

 persistent, sterile, the others deciduous ; sterile flower 3-androns, with the lower 

 glume lanceolate, membranaceous, twisted, much longer than the fertile spikelet 

 and the smooth and short pedicel ; fertile spikelet rusty bearded ; the coriaceous 

 glumes obtuse, many times shorter than the very long (4') contorted and hairy 

 awn. — Indian old fields, Florida and Georp:ia. Introduced? — Glnmc of the 

 sterile spikelet, like the sheaths, rugose on the back. Perhaps identical with 

 A. polystachyus, lioxb. 



57. ERIANTHUS, Michx. 



Tall rccd-liko grasses, with long and flat leaves, and panicled inflorescence. 

 Spikelets by pairs on the slender branches, alike, one pcdicelled, the other ses- 

 sile, both with a hairy involucre at the base. Lower (lower of one palea, neutral ; 

 the upper of two palere, perfect, shorter than the membranaceous nearly equal 

 glumes, the lower one awned. Stamens 2-3. 



1. E. alopecuroides, Ell Culms 4"- 10° higli ; sheaths of Iho I)ro d 

 (C- 12") very ron^ih leaves woolly above, rough below ; panicle (1° - 2° long) 

 woolly, expanding, pyrani;d;il; li.nirs of the involucre conious. twice lis long ns 

 the sparsely hairy glumes ; awn straight. — Var. contoktls ( E. contortu.s, EU.) 



