OBDEB 156. GRAMLNE^E. 791 



highly important grain, ono of tho staple productions of tho soil ; said to hayo 

 been first discovered in the Island of Juan Fernandez. 



(3. NIGRA. BLACK OATS. Palea dark brown, almost black, awnless. 



y. SECUNDA. HORSE-MANE OATS. Panicle 1-sided ; awns short. 



29. TRISETUM, L. (Lai. tria, three, sctum, a bristle ; a character- 

 istic term.) Spikelet 2 5-flowered ; glumes 2, shorter than tho 

 flowers ; lower palea with 2 bristles at the apex and a soft, flexuoua 

 awn from above the middle of the back ; scales ovate ; fruit coated, 

 farrowed. Very closely related to Avena. 



1 T. palustre Torr. Culm erect, contracted at the nodes, slender, smooth, about 

 2f high ; Ivs. lance-linear, about 3' long, roughish, on smooth, striate sheaths ; 

 panicle oblong, contracted, nodding, yellowish-green ; spikelets about B" long, 2 3- 

 jftowered, middle flower abortive, upper one pedicellate, its lower palea ending in 

 2 setous teeth, and awned below the tip, lower one mostly awnless. If Wet 

 meadows, Mass., N". Y. to Fla. May July. (Avena, MX. Aira pallens, 

 Muhl.) 



2 T. molle Kunth. Minutely and softly puberulent throughout; culm If high; Ivs. 

 narrow, 2 to 4' long ; pan. contracted and spike-like, 2' long ; awn at length de- 

 flexed, longer than the beardless flowers. Mts. and rocks, 1ST. H. to Mich, and 

 Can. (Avena, MX.) Scarcely differs from tho foregoing, which is also sometimes 

 downy. 



3 T. purpurascens Torr. Culm leafy, 2f high; Ivs. narrow-linear, keeled, 

 4 G' long, and with the sheaths smooth ; panicle very simple, almost a raceme, 

 few-flowered, 4 6' long ; glumes 3 to 5~ftowered, very unequal, entire ; spikelets 6 

 to 8" long, lanceolate, terete, often purple, smooth ; lower palea 7-veined, cleft 

 into 2 bristly points at the apex; awn geniculate. 2 Mountain bogs, N. Eng. 

 to Wis. and Can. June. 



30. BRO r MUS, L. BROME GRASS. (Gr. /3poym, food; the namo 

 was anciently applied to Oats.) Spikelets 5 to oo -flowered ; glumes un- 

 equal, membranous, veined ; lower pale 5 to 9-veined, convex or cari- 

 nate on the back, awned from below the mostly bifid tip ; upper pale 

 ciliate on the 2 keels, often bifid ; caryopsis linear, adherent to the 

 upper pale. Coarse grasses with flat Ivs. and large, paniculate, nodding 

 spikelets. 



Glumes narrow, the lower l-veined, upper 3-veined. Pale keeled Nos. 6, 5 



Glumes veiny, the lower 3 to 5, upper 5 to 7-veined (a). 



a Lower pule compressed-carinate, the awn scarcely any No. 4 



a Lower pale rounded on the back, the awn conspicuous Nos. 3 1 



1 B. secallmis L. SMOOTH CHEAT OR CHESS. Culm smooth, 2 to 4f high ; Ivs. 

 lance-linear, 6 to 12' long, rough and some hairy above, on smoothish sheaths; 

 pan. spreading in fruit, branches subsimple, with few nodding spikelets ; spkl. 

 ovate, turgid, smooth, 7 to 10-flowered ; fls. soon diverging and rather distinct, 

 oblong, longer than the short, flexuous awn. (J) A handsome but worthless grass, 

 in fields of wheat and other grains, and in waste grounds. Jn., Jl. Eur. 



2 B. mollis L. DOWNY CHESS. Culm slender, some downy, 12 to 18' to 2f; 

 Ivs. flat, hairy both sides, lance-linear, on sheaths clothed with deflexed hairs ; 

 pan. erect, contracted in fruit ; spikekts ovate, compressed, about G-flowered, downy 

 all over ; fls. oblong, closely imbricated, not longer than their straight awn. (g) 

 Wheat fields and waste grounds, rare. Lower pale J longer than the upper. 

 Jn. Eur. Varies in pubescence. (B. racemosus L. (3. arvensis, Ed. 2.) 



3 B. Kalmii Gray. Culm slender, 18' to 3f; Ivs. and sheaths more or less hairy, 

 sometimes excessively so ; pan. simple, small, 3 to 4' long; spkl. drooping, closely 

 7 to 1 2-flowered, densely silky all over ; lower glume 3-veined, upper 5 ; lower 

 pale much longer than the upper, 5 to 7-veined, the awn % of its length. U Dry 

 hilly woods, U. S. and Can. Jn., JL (B. purgans Torr. nee L. fide Prof. 

 Gray.) 



4 B. uniololdea Thunb. & Kth. EESCUE GRASS. Culm 18' to 3f, glabrous; 



