102 Bulletin VII. 1. 



pressed-keeled, acute or acuminate pointed, striate, many-nerved. 

 Palea rigid, tvvo-keeled. Stamens one to three. Styles distinct; 

 stigmas plumose. Grain compressed, oblong, free. 



Erect perennials, with simple culms, broad and flat, or narrow 

 and involute leaves, and narrow and few-flowered, or ample, lax, 

 and many-flowered panicles. 



Species four or five, all North American. Tennessee species 

 three. 



KEY TO THE SPECIES. 



I. Panicle expanded, spikelets 12 to 18 lines long, 9- to 2oflow- 

 ered, drooping on long slender pedicels 3. U. latifolia. 



1. Panicles long and narrow, spikelets 4 to 5 lines long, 4- to 



8-flowered on very short pedicels 2 



2. Sheaths glabrous, leaves i to 3 lines broad . i. U. gracilis. 

 2. Sheaths pubescent, leaves 4 to 8 lines broad 



2. U, LONGIFOLIA. 



1. Uniola gracilis Michx. Slender Spike-grass. 



Plate XXXV. Figure 138. 



A slender grass two to three feet high, with long, narrow leaves 

 and a contracted, wand-like nodding panicle six to eighteen inches 

 long. Sheaths smooth, a little bearded at the throat; ligule short, 

 ciliate; leaves nearly erect, six to twelve inches long, three lines 

 wide or less, tapering to nearly filiform, scabrous tips. Spike- 

 lets three- to five-flowered, three to four lines long, the glumes 

 spreading in fruit. Empty glumes short, unequal; flowering 

 glumes one and one-half to two and one-half lines long, lanceolate 

 and somewhat acuminate-pointed, scabrous on the keel near the 

 apex. Palea arched, one-fourth shorter than the floral glume, 

 scabrous on the keels near the apex. 



Open thickets and along the borders of woods in dry soil. July, 

 August. 



2. Uniola longifolia Scribn. Long-leaved Spike-grass. 



Culms three to four feet high; panicle six to fifteen inches long, 

 the short rigid branches rather remote and more or less spread- 

 ing. Lower leaves a foot long or more and four to eight lines 

 broad, scabrous near the convolute, slender tips and often pubes- 

 cent near the base. Sheaths somewhat compressed and more or 

 less pubescent, with a dense ring of soft hairs on the back where 

 it joins the blade. 



Habit and inflorescences nearly as in U. gracilis, but more ro- 

 bust, main axis and branches of the panicle more rigid. Sheaths 

 pubescent and spikelets somewhat larger. Very distinct from U. 

 fiitida. 



Valley of the Hiwassee (A. Ruth); TuUahoma (Dr. Gattinger.) 



3. Uniola latifolia Michx. Broad-leaved L'niola. 



Plate XXXV. Figure 139. 

 An erect grass with rather stout, simple culms two to four feet 



