Perennial caespitose, stoloniferous, or rhizomatous. Leaf-sheath split to base or margins fused, apical auricles small. Ligule ciliolate. Leaf-blade convolute, or folded; usually persistent; pungent in F. ultramafica; variable in TS. Culms unbranched; nodes glabrous. Inflorescence an open or contracted panicle of 2-many-flowered laterally compressed, pedicelled spikelets disarticulating above the glumes. Glumes unequal or subequal, persistent, ± keeled and ornamented, rarely exceeding lemmas. Lemma lanceolate-acute or awned, rounded on back or slightly carinate, membranous to thinly coriaceous, 5-7-nerved, awn terminal. Palea bidentate, keels scabrid. Flowers ☿, usually chasmogamous. Lodicules 2, unequally lobed, often hair-tipped. Stamens 3. Ovary glabrous or hispid hairy at apex. Caryopsis dorsiconvex, ventrally sulcate, free; embryo small; hilum long, linear. Fig. 6.

Short-lived annuals, rarely perennials; branching intravaginal. Leaf-sheath rounded. Ligule membranous. Leaf-blade flat, convolute when dry. Culm erect or decumbent, branching mainly at base. Inflorescence a narrow, usually secund panicle, usually sparsely branched, or sometimes a spiciform or compound raceme. Spikelets laterally compressed, (1)-3-12-flowered, ☿, the upper 1-2-(3) florets ♂ or Ø; disarticulation above and sometimes below glumes, and below each ☿ floret. Glumes usually very unequal; lower sometimes minute, 1-nerved, or nerves 0, upper 1-3-nerved, acute to acuminate. Lemma (3)-5-nerved, rounded or occasionally keeled, subcoriaceous, acuminate, mucronate or tapering to a long straight awn. Palea ≈ lemma, 2-keeled, apex bifid. Callus rounded or pointed, glabrous or pubescent. Lodicules 2, membranous, bilobed or bidentate, narrow or sometimes ovate. Stamens 1-(3), often small. Ovary apex glabrous or pubescent; styles free. Caryopsis linear to narrowly ellipsoid, dorsiventrally compressed, longitudinally grooved; embryo small; hilum linear, at least ¾ length of caryopsis.