γ. secunda. Horse-mane Oats. Panicle 1-sided; awns short.

29. TRISE'TUM, L. (Lat. tria, three, setum, a bristle; a characteristic term.) Spikelet 2 - 5-flowered; glumes 2, shorter than the {lowers; lower palea 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, smooth, 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-flowered, middle flower abortive, upper one pedicellate, its lower palea ending in 2 setous teeth, and awned below the tip, lower one mostly awnless. -Order CLVI Gramineae Grasses Part 14 2568 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; 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 5-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. -Order CLVI Gramineae Grasses Part 14 2569 Mountain bogs, N. Eng. to Wis. and Can. June.

30. BROM'US, L. Brome Grass. (Gr.Order CLVI Gramineae Grasses Part 14 2570 food; the name was anciently applied to Oats.) Spikelets 5 to ∞-flowered; glumes unequal, 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 lvs. and large, paniculate, nodding spikelets.

§ Glumes narrow, the lower 1-veined, upper 3-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 ovate, turgid, smooth, 7 to 10-flowered; fls. soon diverging and rather distinct, oblong, longer than the short, flexuous awn. -Order CLVI Gramineae Grasses Part 14 2571 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, lvs. flat, hairy both sides, lance-linear, on sheaths clothed with deflexed hairs; pan. erect, contracted in fruit; spikelets ovate, compressed, about 6-flowered, downy all over; fls. oblong, closely imbricated, not longer than their straight awn. -Order CLVI Gramineae Grasses Part 14 2572Order CLVI Gramineae Grasses Part 14 2573 Wheat fields and waste grounds, rare. Lower pale 1/4 longer than the upper. Jn. § Eur. Varies in pubescence. (B. racemosus L. β. 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 12-flowered, densely silky all over; lower glume 3-veined, upper 5; lower pale much longer than the upper, 5 to 7-veined, the awn 1/3 of its length. -Order CLVI Gramineae Grasses Part 14 2574 Dry hilly woods, U. S. and Can. Jn., Jl (B. purgans Torr. nee L. fide Prof. Gray.)

4 B. unioloides Thunb. & Kth. Rescue Grass. Culm 18' to 3f, glabrous; lvs. smoothish, on sheaths more or less hairy or almost smooth; pan. large, 6 to 10' long, branches subsimple, whorled; spikelets smooth, lance-ovate, much compressed, 2-edged, 1' long, 1/3 as wide, 8 to 12-flowered; lower glume 3, upper 6-veined; lower pale 7 to 9-veined, much larger than the strongly 2-keeled upper, with scarcely any awn. -Order CLVI Gramineae Grasses Part 14 2575 Cultivated at the South (in 1857) from seeds distributed by the government, but proved no better than our Chess, † Peru.

5 B. ciliatus L. Culm erect, smooth, 2 to 4f high; lvs. flat, some pubescent, C to 12' long, on sheaths more or less pilous with deflexed hairs; pan. large, erect, 5 to 8' long, finally nodding, branches in 2s and 4s, compound; spikelets at first lance-fusiform, 7 to 11 -flowered, the fls. soon separating; glume lower 1, upper 3-veined; peles compressed-carinate above, silky-haired near the margins, twice longer than the straight awn. -Order CLVI Gramineae Grasses Part 14 2576 Damp woods along rivers, U. S. and Can. Jn., Jl. (B. Canadensis Mx. B. pubescens Muhl. B. purgans, Ed. 2.)

β. purgans. Pan. more open; spkl. silky-hairy all over. - Mid. and S. States.

6 B. tectoram L. Culm slender, 1 to 3f, pubescent above; lvs. pubescent; sheaths ciliate with few long hairs; pan. compound, at length 1-sided and nodding; pedicels capillary; spikelets linear-oblong, minutely downy, about 5-flowered; glumes lower 1-, upper 3-veined; lower pale 3-veined, carinate. scarious-edged, lance-subulate, scarcely as long as its awn. -Order CLVI Gramineae Grasses Part 14 2577 N. York (Sartwell), Penn. (Jackson). (B. sterilis Torr.) §

31. TRICUS'PIS, Beauv. (Lat. tres, three, cuspis, a point; referring to the structure of the lower pale.) Spikelets terete or tumid, 3 to 9-flowered, upper flower abortive; glumes 2, unequal, awnless; pales 2, the lower larger, hairy-fringed along the keel and the 2 lateral veins, and ending in 3 short cusps or mucrones (the projecting veins and mid-vein) and 2 intermediate teeth, upper pale 2-toothed; stamens 1 to 3; stigmas plumous; caryopsis smooth, free, 2-horned. - Erect, simple. Fan. mostly with racemous branches.