556 GRAMINE^E. (GRASS FAMILY.) 



formis, Nutt. Uralepis rnproa, Ki inth.) Dry or sandy fields, S. New York to 

 Illinois, and southward. Aug. A showy grass, with the spreading panicle 

 sometimes 1 wide. Points of the lower palea almost equal, scarcely exceeding 

 the intermediate teeth, thus appearing 5-toothed. 



12. TRITLASIS, Bcauv. (Dipi.Vea, If, if. Uralepis, Xult.) Glumes much 

 shorter tin in lite somticluit remote flowers: both pal,ccu strongly fringe-bearded ; the 

 lower 2-cleJl at the summit, its mid-nerve produced into an awn between the truncate 

 or awn-pointed divisions. 



2. T. pui'purea. (SAND-GRASS.) Culms many in a tuft from the 

 same root, ascending (6'- 12' high), with numerous bearded joints ; leaves invo- 

 lute-awl-shaped, mostly short ; panicles very simple, bearing few 2 - 5-flowered 

 spikelcts, the terminal one usually exserted, the axillary ones included in the 

 commonly hairy sheaths ; awn much shorter than the pa/ea, frequently not exceeding 

 its eroded-truncate or obtuse lateral lobes. ? (Aira purpurea, Walt. Diplocea 

 barbata, Raf. Uralepis purpurca and U. aristulata, Nutt.) In sand, Massa- 

 chusetts to Virginia along the coast, and southward. Aug., Sept. Plant acid 

 to the taste. 



T. coBNtTA (Uralepis cornuta, Ell. and Triplasis Americana, Beauv. !) may 

 perhaps extend north to the borders of Virginia. 



25. DUPONTIA, E. Brown. DUPONTIA. 



Spikelets 2 - 4-flowered, rather terete. Glumes membranaceous, nearly equal- 

 ling the remote flowers. A cluster of villous hairs at the base of each flower. 

 Palea} thin and membranaceous or scarious ; the lower one convex, scarcely 

 keeled, faintly nerved, entire, mostly acutish, pointless. Stamens 3. Stigmas 

 plumose. Ovary glabrous. Perennial and chiefly Arctic grasses, with linear 

 flat leaves, their sheaths closed at the base, the spikelets in a loose panicle. 

 (Named for M. Dupont, a writer on the sheaths of the leaves of Grasses.) 



(A genus, according to its author, most allied to Deschampsia (Aira), from 

 which it differs in its entire and awnless palea?, an alliance strengthened by 

 the following remarkable new species which I venture to place in it ; leaving 

 the genus among the Festueineae on account of the technical character, as it 

 wants the awn, and because it may include Arctophila of Kuprecht, which verges 

 very close on Colpodium and (ilyceria. Fluminia, Fries, or Scolochloa, Link, 

 (which may occur within our northwestern borders,) i.s intermediate in character 

 between Dupontia and Tricuspis, but might perhaps be ranged with Arctophila 

 in spite of its teeth, of which there arc traces in some genuine Glyceriaj.) 



1. D. Coolcyi. Tall (2 or more high) ; leaves roughish, sparsely hairy 

 above ; panicle ample, compound ; glumes very unequal, the upper (3" long) 

 scarcely shorter than the spikelet, their midrib and the pedicels rough, the slen- 

 der rhachis conspicuously and unilaterally bearded for its whole length. Bor- 

 ders of a swamp, Washington, Macomb County, Michigan. Flowers in the 

 spike mostly 2 or 3 and a sterile pedicel, whitish, the palea longer and of a 

 firmer texture than those of Aira < a'spitosa and A. P-otlinica, perfectly entire, 

 acntMi, and with a somewhat ke-'l-likf n>iighi.>h midrib : no trace of an awn. 



