Order 156.— GRAMINE^I. 791 



highly important grain, one of the staple productions of the soil ; said to have 

 been first discovered in the Island of Juan Fernandez. 



/3. nigra. Black Oats. Palea dark brown, almost black, awnles». 



y. secunda. IIorse-mane Oats. Panicle 1-sided; awns short. 



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

 istic term.) Spikclet 2 — 5-tlowered ; glumes 2, shorter than the 

 flowers; lower palca with 2 bristles at the apex and a soft, flexuous 

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

 furrowed. — Very closely related to Avena. 



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

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

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

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



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

 meadows. Mass., N. Y. to Fla. May — July. (Avena, Mx. Aira pallens, 

 Muhl.) 



2 T. molle Kunth. Minutely and softly pub erulent throughout ; culm If high; lvs. 

 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, N. H. to Mich, and 

 Can. (Avena, Mx.) Scarcely differs from the foregoing, which is also sometimes 

 downy. 



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

 4 — 6' long, and with the sheaths smooth ; panicle very simple, almost a raceme, 

 few-flowered, 4 — 6' long ; glumes 3 to b-flowered, 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. — U Mountain bogs, N. Eng. 

 to Wis. and Can. June. 



30. BRCTMUS, L. Brome Grass. (Gr. (3pcJjj,a, food; the name 

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

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

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

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

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

 spikelets. 



| Glumes narrow, the lower 1 -veined, upper o- veined. Pale keeled Nos. 6, 5 



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



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



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



1 B. secalinus L. Smooth Cheat or Chess. Culm smooth, 2 to 4f high ; lvs. 

 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. 

 ovale, 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'to2f; 

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

 pan. erect, contracted in fruit ; sp>ikelets ovate, compressed, about G-flowered, downy 

 all over ; fls. oblong, closely imbricated, not longer than their straight awn. — CD (2) 

 Wheat iields and waste grounds, rare. Lower pale \ longer than the upper. 

 Jn. § Eur. Varies in pubescence. (B. racemosus L. j3. arvensis, Ed. 2.) 



3 B. Kalmii Gray. Culm slender, 18' to 3f; lvs. 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 i of its length. — U Dry 

 hillv woods, TJ. S. and Can. Jn., Jl. (B. purgans Torr. nee L. fide Prof. 

 Gray.) 



4 B. unioloides Thunb. & Kth. Rescue Grass. Culm 13' to 3f, glabrous; 



