Obdeb 156.— GRAMINEA ^91 



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

 been tirst discovered in the Island of Juan Fernandez. 



/3. NIORA. Black Oats. PoiecE' darlc brown, almost black, awnless. 



y. SECUNDA. Horse-mane Oats. Panicle l-aided ; awns ahoit. 



29. TRISE'TUM, L. (Lat. tria, three, setum, a bristle ; a character 

 islic term.) Spikelet 2 — 5-flowered ; glumes 2, shorter than the 

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

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

 furrowed. — Veiy closely related to Avena. 



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

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

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

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

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

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

 Muhl.) 



2 T. molle Kunth. Minutely andjpflly puberuleni ihrovgkdut; culm If high; Its. 

 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; Ivs. narrow-linear, keeled, 

 4 — tJ' 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 tho apex; awn geniculate. — If Mountain bogs, N. Eng. 

 to Wis. and Can. June. 



30. BRO^fflUS, L. Brome Grass. (Gr. (ipufia, food ;' the name 

 was anciently applied to Oats.) Spikelets 6 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. 



5 Glumes narrow, the lower l-veined, upper )J-veine(l. Pale keeled Noe. C, 5 



§ Glumes vfiny, the lower 3 to 5, upper 5 to 7-veine(l (a). 



a Lower jiale eompressed-carinate, tlio own scarcely any No, 4 



a Lower pale rounded on tho back, the awn conspicuous No.s. 3 — 1 



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

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

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

 mate, turgid, smooth, 1 to 10-flowered ; fls. soon diverging and rather distinct, 

 oblong, longer than the short, flexuous awn. — 3) A handsome but worthless grass, 

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



2 B. mollis L. Downy Chess. Culm slender, some downy, 13 to 18'to2f; 

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

 pan. erect, contracted in fruit ; spikelets ovate, ccmpi-essed, about G-flowered, downy 

 aU over ; fls. oblong, closely imbricated, not longer than their straight awn. — (D @ 

 Wheat fields and waste grounds, rare. Lower pale i longer than tho upper. 

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



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

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

 \ to 12-flowered, densely silky all over; lower glume 3-veined, upper 5; lov)er 

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

 hilly woods, TJ. S. and Caa Jn., Jl (B. purgans Torr. nee L. flde Prof! 

 Gray.) 



4 B. unioloides Thunb. &, Kth. Eescbb Grass. Culm 18' to 3f, glabrous; 



