600 CLXI. GRAMINE^E. PSAMMA 



long ; palece 5- veined, a little shorter than the upper glume ; sta. 3 ; stig. plu- 

 mose. 1\. N. J. to Car. Aug. 

 /?. laxa. Panicle more loose, with long, green branches. White Mts. 



5. T. CONCINNA. Wood. (Agrostis concinna. Tuckm.) 



St. low, erect ; Ivs. filiform-setaceous ; pan. ovate, spreading, glabrous ; 

 gl. unequal, lower acute-mucronate, rougkish above, upper acute, glabrous ; 

 palece glabrous, awn from below the middle, contorted, scabrous, exceeding the 

 flower, with a few hairs at its base. White Mts. Tuckerman. The species are 

 not valuable in agriculture. 



9. MUHLENBERGIA. Schreb. 



^ * . In honor of the late Henry Muhlenberg, D.D., a well known, eminent botanist. 



Panicle nearly simple ; glumes 2, very minute, unequal, fringed ; 

 palese many times longer than the glumes, linear-lanceolate, veined, 

 hairy at base ; the lower one terminating in a long awn. 



1. M. DIFFUSA. Schrb. Dorp-seed Grass. 



St. decumbent, diffuse, branching, slender, compressed ; branches assurgent ; 

 Ivs. 2 3' by 2", linear-lanceolate, rough, with smooth, striate, open sheaths ; 

 panicles terminal and lateral, with remote, appressed, rough branches ; spikeleis 

 pedicellate, often purple ; awn about as long as the paleee. Ij. Borders of woods 

 and fields, N. Eng. to Car. and Ky. Aug. 



2. M. ERECTA. Roth. (Brachyelytrum aristatum. Palis.') 



St. erect, simple, retrorsely pubescent at the nodes, 2 3i high ; Ivs. lanceo- 

 late, scabrous, ciliate on the margin, 4 6' long, 3" or more wide, with some- 

 what open sheaths ; panicle terminal, simple racemose, contracted ; spikeleti 

 pedicellate, large ; glumes very unequal, upper one subulate ; lower palea half as 

 long as its awn, upper polece with a short awn at base lodged in the dorsal 

 groove. Tj. Rocky hills, Can. and U. S., frequent. July. 



10. CINNA. 



Glumes 2, subequal, compressed, without involucre or awns, upper 

 one 3-veined ; palese 2, naked at base, on sLort stipes, lower one 

 larger, enclosing the upper, with a short awn a little below the tip ; 

 stamen 1. 



C. ARUNDINACEA. Willd. (Agrostis Cinna. Lam. A. monandra. Hornem.) 

 St. simple, erect, smooth, 3 5f high ; Ivs. linear-lanceolate, 12 18' by 3 5'' 

 pale green, rough-edged, with smooth, striate sheaths ; slip, long, lacerated ; 

 panicle near a foot in length, rather attenuated above and nodding, with the 

 branches capillary, drooping, and arranged somewhat in 4s ; glumes linear-lan- 

 ceolate ; lower palece with a short, straight awn a little below the tip. Ij. A 

 beautiful grass, sought by cattle, in rich, shady soils, U. S. and Can. Aug. 



11. TRICHOCHLOA. DC. 



Gr. rpi%) rpi%os, hair, %Aoo, grass ; from the capillary inflorescence. 



Glumes 2, very minute; paleae many times longer than the 

 glumes ; naked at base, lower one convolute at base, terminating in 

 a long, unarticulated awn. 



becoming 



branches 1 4' long, in pairs, and as fine as hairs ; spikelets purple ; lower pnlca 

 produced into an awn 3 or 4 times its length. 7J. An exceedingly delicate grass, 

 with large, purple, glossy and almost gossamer-like panicles, waving in the 

 breeze. Sandy soils. Jn. Jl. 



12. PSAMMA. Palis. 



Gr. i//a/*//oj, sand ; in which this grass grows on the sea shore. 



Panicle spicate; glumes 2, awnless; paleae 2, shorter than the 



