G R A M J N A C E A: . 43 I 



6. A tenuiflvra, Willd. : culm nearly simple, pubescent about the joints ; 

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

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

 spikelet. Muhlenbergia Willdenovii Trin. 



Rocky woods. Can. to Car. July, Aug. %. Root creeping. Culm 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. sylvatica Torr. : culm ascending, much branched, diffuse, smooth ; 

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

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

 bergia sylvatica Torr ($ Gr. 



Rocky hills. N. Y. to Virg. Aug. %. Root creeping. Culm 23 feet 

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

 fuse. Spreading Bent-grass. 



8. A. compressa 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. 1\.. Root creeping. Culm soboliferous. 

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



Compressed Bent-grass. 



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

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

 unequal glumes. A. Indica Muhl. 



Sandy barrens. N. J. to Flor. Oct. %. Culm 12 feet high, terete. 

 Panicle purple. Rush-like Bent-grass. 



10. A. canina Linn. : var. 1 tenetta 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 N. Y. Aug. f 4- 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. Brown Bent-grass. 



20. TRICHODIUM. Mich. Thin Grass. 



(From the Greek 0pi, hair, and ei6os,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. Gary op- 

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



1. T. laxiflorum Mich.: culm erect; leaves lance-linear, short, the 

 sheaths somewhat rough; panicle diffuse, capillary, with trichotomous 

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

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



Dry fields. Subarct. Amer. to Car. May, June. f L\..Culm 18 inches 

 high, very slender. Lower leaves 36 inches long, becoming involute and fili- 



