20 Bulletin VIL 1. 



spikelet: empty glumes smooth or with a few long hairs above, 

 first glume lanceolate acuminate, two-toothed at the apex, scabrous 

 along the keels above; second glume lanceolate acuminate, equal- 

 ing the first glume and similar in texture; third glume lan- 

 ceolate acuminate, acute or rarely awned, three-nerved, ciliate on 

 the margins above; fourth glume lanceolate, shorter than the 

 third, three-nerved below and awned from the entire apex, awn 

 straight about ten lines long. Palea small, ovate. Inner glumes 

 and fimbriated lodicules dark purple. — Oakland Station, near Tul- 

 lahoma (A. Gattinger). August to September. 



In the University herbarium there is a specimen from Sumner 

 County ticketed by Dr. Gattinger, ''E. brevibarbisy As there is no 

 specimen of E. brevibarbis in the collection from Dr. Gattinger, 

 this may be the plant referred to in his "Tennessee Flora" as 

 growing near Mitchellville. . 



7. ANDROPOGON Linn. Sp. PI. 1045 (1753)- 



Spikelets in pairs at each joint of the articulate and usually 

 hairy rachis of the short racemes or false spikes, one sessile and 

 hermaphrodite with four glumes, the other pedicellate, staminate 

 (ver)^ rarely hermaphrodite), neuter, reduced to a mere rudiment 

 or even wholly absent, the hairy pedicel alone remaining. Ra- 

 cemes solitary, in pairs or variously clustered and paniculate, 

 often subtended by a sheathing bract (the spathe.) Outer glumes 

 subequal, much firmer in texture than the inner ones. First 

 glume of the sessile spikelet coriaceous or cartilaginous (rarely 

 herbaceous), flattened or depressed upon the back with one 

 nerve near each margin stronger than the others, forming two 

 keels; second glume more pointed than the first and more or less 

 keeled, at least above; the third glume herbaceous or hyaline, a 

 little shorter than the outer ones, empty; the fourth or flowering 

 glume hyaline, entire, or more or less bifid at the apex and awned. 

 Awn terminal or from between the teeth of the glume, straight 

 or more often twisted in the lowef part (the column), bent near 

 the middle and very slender above. Palea usually present, hya- 

 line and nerveless, rarely more than half the length of its glume. 



Slender or rather coarse perennials with solid culms, growing 

 chiefly in dry, sandy or poor soil. 



Species about one hundred and eighty, widely distributed over 

 both hemispheres, especially in the tropical and sub-tropical 

 regions. Thirty-five species are recorded as being found within 

 the United States. Those enumerated below have been found in 

 Tennessee. 



KEY TO THE SPECIES. 



I. Racemes 1-5, terminal on the culm or its branches and sub- 

 tended by a spathe-like bract 2 



1. Racemes in terminal bractless panicles 7 



2. Hairs on the joints of the rachis and pedicels shorter than 



the spikelets 3 



2. Hairs longer than the spikelets '4 



