73. Graminaceous Plants. Graminaceae

* Spikelets of one perfect terminal flower, with or without a perfect male flower below it.

† Flowering glumes of a firmer texture than the empty ones below (Paniceae).

(305) Milium - panicle loose; spikelets one-flowered; glumes two, flattish, equal; pales two, equal, awnless; stamens three; styles two.

†† Two male or imperfect florets or minute rudimentary glumes below the perfect flower, besides the outer empty glumes (Phalarideae.)

(306) Digraphis - panicle somewhat contracted; glumes two, keeled, equal, each with a tuft of hairs at its base, representing an abortive floret; pales two, equal, awnless; stamens 3; styles 2.

** Spikelets with one or more perfect flowers, the male or rudimentary, if any, terminal.

† Spikelets one-flowered, usually pedicellate (Agrostidese).

(307) Phleum - panicle spiked; glumes two, keeled, equal, longer than the pales, with an awn proceeding from the midrib; pales two, equal, awnless, membranous; stamens three; styles two.

(308) Alopecurus - panicle spiked; glumes two, equal, keeled, often connate at the base; pale single, with an awn arising from its base, ribbed; stamens three; styles two.

(309) Lagurus - panicle contracted, ovate; glumes two, equal, terminating in a long plumed awn; pales two, the lower with a dorsal twisted awn, bifid at the apex, the lobes long, sharp, awn-like; stamens three; styles two. 310) Polypogon - panicle contracted, oblong; glumes two, equal, the lower awned under the apex, the upper from the apex; pales two, equal, convex, the lower awned beneath the apex; stamens three; styles two.

(311) Agrostis - panicle loose; glumes two, nearly equal, the upper smaller, acute, without awns; pales shorter, often bearing an awn below the middle, the inner sometimes wanting; stamens three; styles two.

(312) Apera - panicle loose; glumes two, acute, the lower smaller, nearly equal, without awns; outer pales with a hairlike awn, 3-4 times as long as the spikelet; stamens three; styles two.

(313) Ammophila - panicle contracted, cylindrical; glumes two, keeled, unequal, awnless, the lower smaller; pales two, the lower awned under the apex, with hairs at the base; stamens three; styles two.

(314) Calamagrostis - panicle somewhat spreading; glumes two, convex, nearly equal, keeled, pointed; pales two, unequal, membranous, ribbed, surrounded with hairs at the base, the lower awned; stamens three: styles two.

†† Spikelets two- or few-flowered, pedicellate, the flowering glumes (pales) usually shorter than the outer ones, their awns often bent or tivisted (Aveneae).

(315) Aira - panicle loose; spikelets small; florets equally perfect; glumes two, nearly equal; pales two, the lower bifid, with a dorsal straight or slightly-twisted awn; stamens three; styles two.

(316) Avena - panicle loose; spikelets large; upper florets sterile and imperfect; glumes two, nearly equal; pales two, knee-bent, the lower bifid, with a twisted dorsal awn; stamens three; styles two.

(317) Trisetum - panicle oblong, somewhat spreading; spikelets small, crowded; florets equally perfect; glumes two; pales two, the lower deeply cleft, with a twisted, dorsal, knee-bent awn; stamens three; styles two.

(318) Arrkenatherum - panicle loose; upper floret hermaphrodite with a rudimentary prolongation of the axis, lower male; glumes two, nearly equal; pales two, the lower emarginate, that of the male floret with a twisted awn at the base, that of the hermaphrodite floret with a small straight awn under the apex; stamens three; styles two.

(319) Holcus - panicle somewhat open; lower floret hermaphrodite, the upper male; glumes two, nearly equal, boat-shaped; pales two, the outer of the male florets awned under the apex, of the hermaphrodite floret awnless; stamens three; styles two.

††† Spikelets one-flowered, sessile along one side of the simple linear branches of the panicle (Chlorideae).

(320) Spartina - panicle of 2-4 erect, spike-like branches; spikelets in two rows, pressed close to the rachis; glumes two, unequal; pales two, nearly equal, both keeled; stamens three; styles two.

†††† Spikelets one- or several-floicered, sessile in the notches of a simple spike (Hordeineae).

‡ Spikelets one-flowered.

(321) Lepturus - spike slender, cylindrical; glumes two, hard, ribbed; pales two, thin, awnless, about as long as the glumes; stamens three; styles two.

(322) Nardus - spike slender, simple, one sided; glumes none; pales two, the outer wrapping up the inner, which is flat; stamens three; style one.

(323) Hordeum - spikes cylindrical, dense; spikelets in threes, 1-2 usually neuter or barren; fertile ones with one perfect floret and a rudimentary neuter one; glumes two, collateral, awned; pales two; stamens three; styles two.

‡‡ Spikelets several flowered.

(324) Elymus - spike cylindrical, rather dense; spikelets in pairs, each containing 2-4 florets; glumes two, collateral, awnless; pales two, less pointed than the glumes; stamens three; styles two.

(325) Triticum - spike simple; spikelets solitary, sessile, transverse to the rachis, many-flowered; glumes two, opposite, nearly equal, embracing the flowers; pales two, lanceolate, the outer acuminate or awned, the inner bifid.

(326) Lolium - spike elongated, simple, compressed; spikelets at right angles with the rachis, with a bract at the base of each; glumes two, lateral, often deficient; pales two, nearly equal; the outer sometimes awned under the apex; stamens three; styles two.

(327) Brachypodium - spike simple; spikelets transverse to the rachis, with a short pedicel; glumes two, unequal, shorter than the lower florets; pales two, the lower awned under the point, or awnless; stamens three; styles two.

††††† Spikelets several-flowered, pedicellate; awns, if any, straight (Festuceae).

‡ Pales awned.

(328) Bromus - panicle loose; spikelets laterally compressed; glumes two, unequal, shorter than the lower florets; pales two, the lower awned under the apex, very seldom awnless; stamens three; styles two.

(329) Festuca - panicle loose; spikelets laterally compressed; glumes two, unequal, or nearly equal, acute; pales two, the lower mucronate or awned at the point; stamens three; styles two.

(330) Dactylis - panicle loose or somewhat contracted, the terminal ramifications always very short; spikelets clustered, horizontal; glumes two, unequal-sided; pales two, the lower awned under the apex; stamens three; styles two.

(331) Cynosurus - panicle contracted, spike-like, unilateral; spikelets two- or mam-flowered, distichous, with a pectinated involucre at the base; glumes two, equal; pales two, the lower awned from the apex or mucronate; stamens three; styles two.

‡‡Pales aimless.

(332) Briza - panicle loose; spikelets cordate; glumes two equal, convex, about as long as the lower florets; pales two, awnless, the outer boat-shaped; stamens three; styles two.

(333) Poa - panicle loose, seldom contracted; spikelets two- or many-flowered, ovate; glumes two, rather unequal, usually keeled; pales two, nearly equal, awnless, scarious at top; stamens three; styles two.

(334) Glyceria - panicle loose; spikelets cylindrical; glumes two, nearly equal, obtuse; pales two, nearly equal, awnless; stamens three; styles two.

(335) Catabrosa - panicle loose; spikelets two-flowered; glumes two, unequal, rounded or truncate, much shorter than the florets; pales two, nearly equal, truncate, awnless; stamens three; styles two.

(336) Melica - panicle loose; spikelets ovate; glumes two, nearly equal, about as long as the florets; pales two, unequal, awnless; stamens three; styles two.

(337) Arundo - panicle loose; spikelets many-flowered, the lower floret male and naked, the upper hermaphrodite and surrounded by hairs; glumes two, the lower smaller, the upper about as long as the florets; pales two, unequal, pointed; stamens three; styles two.

III. - Species And Varieties