49. BÙCHLOË, Engelm. Buffalo Grass. ([Pl. 16.])
Spikelets diœcious (rarely monœcious), very unlike; the staminate 2–3-flowered, sessile in 2 rows in short 1-sided spikes, the empty glumes blunt, 1-nerved, very unequal, the flowering larger, 3-nerved, a little exceeding the 2-nerved palet; fertile spikelets 1-flowered, in a contracted, capitate, 1-sided spike, the large outer glumes indurated, 3-fid at the apex, united at base and resembling an involucre, the inner (lower) much smaller and membranaceous, or in the lowest spikelet resembling the outer; flowering glume narrow, hyaline, bifid or nearly entire, enclosing the 2-nerved palet. Styles distinct. Grain ovate, free.—A perennial, creeping or stoloniferous, with narrow flat leaves; staminate spikes (2–3) in a pedunculate spike, the pistillate pair sessile in the broad sheaths of the upper leaves. (Name a contraction of Bubalochloë, from βούβαλος, buffalo, and χλόη, grass.)
1. B. dactyloìdes, Engelm. Low (3–8´ high) and broadly tufted; sterile spikes 3–6´´ long, the fertile heads 3´´ long.—Plains of the Sask. to Minn., Kan., and Tex. One of the most valuable grasses of the plains.
50. TRIÒDIA, R. Br. ([Pl. 10.])
Spikelets 3–12-flowered, somewhat terete, the rhachis with bearded joints; terminal flower abortive. Empty glumes unequal; flowering glumes membranaceous or somewhat chartaceous, much larger than the 2-toothed palet, convex, 2–3-toothed or cleft at the apex, conspicuously hairy-bearded or villous on the 3 strong nerves, of which the lateral are marginal or nearly so and usually excurrent, as is the mid-nerve especially, into a short cusp or awn. Stamens 3. Stigmas dark purple, plumose. Grain oblong, nearly gibbous.—Leaves taper-pointed; sheaths bearded at the throat. Panicle simple or compound; the spikelets often racemose, purplish. (Name from τρι-, three, and ὀδούς, a tooth, alluding to the flowering glume.)
§ 1. TRIODIA proper. Glumes shorter than the crowded flowers, the flowering one 3-cuspidate by the projection of the nerves, and usually with intermediate membranaceous teeth; palet naked.
1. T. cùprea, Jacq. (Tall Red-top.) Perennial; culm upright (3–5° high), very smooth, as are the flat leaves; panicle large and compound, the rigid capillary branches spreading, naked below; spikelets very numerous, 5–7-flowered, shining, purple (4´´ long); the flowering glumes hairy toward the base, their points almost equal, scarcely exceeding the intermediate teeth, thus appearing 5-toothed. (Tricuspis seslerioides, Torr.)—Dry or sandy fields, southern N. Y. to Mo., and southward. Aug.—A showy grass, with the spreading panicle sometimes 1° wide.
§ 2. TRIPLÀSIS. Glumes much shorter than the somewhat remote flowers; flowering glume and palet strongly fringe-bearded, the glume 2-cleft at the summit, its mid-nerve produced into an awn between the truncate or awn-pointed divisions.
2. T. purpùrea, Hack. (Sand-Grass.) Culms many in a tuft from the same annual root, ascending (6–12´ high), with numerous bearded joints; leaves involute-awl-shaped, mostly short; panicles very simple, bearing few 2–5-flowered spikelets, the terminal one usually exserted, the axillary ones included in the commonly hairy sheaths; awn much shorter than the glume, seldom exceeding its eroded-truncate or obtuse lateral lobes. (Tricuspis purpurea, Gray.)—In sand, Mass. to Va. along the coast, and southward; also L. Erie, near Buffalo, and Ill. Aug., Sept.—Plant acid to the taste.
51. DIPLÁCHNE, Beauv. ([Pl. 9.])