GRAMINACEiE. 431 



6. A lenuijlm'a Willd. : culm nearly simple, pubescent about the joints ; 

 branches appressed ; panicle contracted, filiform ; paleae twice as long as 

 the glume, hairy at base, the lower one three or four times as long as the 

 spikelet. Muhlenberg ia Willdenovii Trin. 



Rocky woods. Can. to Car. 'July, Aug. %.. — Root creeping. CmZot 3 feet 

 or more high, with swelling and pubescent nodes. Leaves few, spreading, 

 strongly nerved. Panicle elongated, very slender and contracted. 



Slender-flowered Bent-grass. 



7. A. sylvalica Torr. : culm ascending, much branched, diffuse, smooth ; 

 panicle slender, rather dense-flowered ; paleae longer than the glumes ; 

 awn about three times as long as the flower. A. dijffhcsa Muhl. Muhlen- 

 bergia sylvatica Torr <^ Gr. 



Rocky hills. N. Y. to Virg. Aug. %..—Root creeping. Culm 2—3 feet 

 high. Resembles the preceding, but differs in being much branched and dif- 

 fuse. Spreading Bent-grass. 



8. A. comp-es&a Torr. : whole plant very smooth ; culm erect, compressed, 

 simple ; panicle oblong, subcontracted ; glumes equal, shorter than the 

 paleae, acute ; paleae rather obtuse, smooth at the base. 



Sandy swamps. N. J. Sept. %. — Root creeping. Culm soboliferous. 

 Leaves linear, long, compressed, with carinate sheaths. Panicle purple. 



Compressed Bent-grass. 



9. A. juncea Mich. : leaves straight and erect, convolutely setaceous ; pan- 

 icle oblong-pyramidal, verticillate : paleae awnless, twice the length of the 

 unequal glumes. A. Iiidica Miihl. 



Sandy barrens. N. J. to Flor. Oct. 1\.. — Culm 1 — 2 feet high, terete. 

 Panicle purple. Rush-like Bent-grass. 



10. A. canina Linn. : var. 1 ienella Torr. : panicle loose, somewhat 

 contracted ; the branches mostly in threes, slightly hispid ; glumes nearly 

 equal, lanceolate, very acute, rough on the keel ; lower palea narrow-lan- 

 ceolate, rather acute, with a geniculate awn a little below the middle ; the 

 awn about twice the length of the flower ; upper palea nearly wanting, 

 {Torr. N.Y. Fl.) 



• Mountains in Northern IN. Y. Aug. %. — Culm about a foot high, slender, 

 smooth. Leaves very narrow, flat. Panicle very slender, the branches some- 

 what flexuous. Differs from A. canina in its less diffuse panicle, narrow glumes 

 and flat leaves. Brovm Bent-grass. 



20. TRICHODIUM. Mich.— Thin Grass. 



(From the Greek 0pi|, hair, and et6os,form ; in allusion to the hair-like inflo- 

 rescence.) 



Glumes 2, nearly equal, very acute, scabrous on the keel. 

 Palea 1, shorter than the glumes, sometimes awned. Caryop- 

 sis loose, covered by the palea. — Flowers in loose panicles. 



1, T.laxijlorum Mich.: culm erect; leaves lance-Unear, short, the 

 sheaths somewhat rough ; panicle difluse, capillary, with trichotomous 

 branches ; glumes unequal, aculeate-hispid on the keel. T. montanum 

 Torr. FL Agrostis laxijlora Richardson. A. Michauxii Trin. 



Dry fields. Subarct. Amer. to Car. May, June. %.—Culm 18 inches 

 high, very slender. Lower leaves 3 — 6 inches long, becoming involute and fill- 



