582 GKAMINE^. (GBASS FAMILY.) 



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

 the glumes ; hairs of the very slender rachis long and glossy. (A. argenteus, 

 Ell., not of DC.) — Wet or dry pine barrens, Florida to North Carolina. Sept. 

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

 and by the silvery haii-s 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 sheaths, 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 included in the more 

 inflated sheaths. A. dissitiflorus, Michx. 1 A. gracilis. Carpenter, the spikes 

 borne at the summit of elongated simple branches. _) — Barren, soil, Plorida to 

 Mississippi, and northward. Sept. and Oct. 



9. A. macrourus, 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, alteraate, solitary, simple, 

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

 than the glume; flowers 3-androus; paleas somewhat villous; awn long, con- 

 torted." Michx. In Carolina. { * ) 



5 2. HETEROPOGON. — Upper flower staminate or pistillate. 



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

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

 slender filiform-pointed sheaths ; spikelets large, the two lowest pairs glurae-iikc, 

 persistent, sterile, the others deciduous ; sterile flower 3-androus, 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 Georgia. Introduced ? — Glume of the 

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

 A. polystachyus, Roxb, 



57. ERIANTHUS, Michx. 



Tall reed-like grasses, with long and flat leaves, and panicled inflorescence. 

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

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

 the upper of two pale£e, perfect, shorter than the membranaceous nearly equal 

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



1. E. alopecuroides. Ell Culms 4°-10° high; sheaths of the broad 

 (6" - 12") very rough leaves woolly above, rough below ; panicle (1° - 2° long) 

 woolly, expanding, pyramidal ; hairs of the involucre copious, twice as long as 

 the sparsely hairy glumes ; awn straight. — Var. contoktus. (E. contortus. Ell.) 



