genus descriptions: SSAs

Long-pedicelled spikelet falling separately, not noticeably compressed, somewhat terete; glumes +/- equal, dissimilar, awnless; lower glume firmly chartaceous to coriaceous, glabrous to hairy, finely 2-keeled upwards, margins inflexed, very narrow, obscurely nerved; upper glume thinner, grooved on either side of rounded keel. Florets 2, lower floret sterile, reduced to a lemma, hyaline, 2-nerved, ciliate or ciliolate upwards, awnless; upper floret bisexual; lemma stipitiform, less firm than glumes (hyaline at base), passing into a flexuous or geniculate, hairy awn; callus pungent to acute, densely hairy, obliquely attached to pedicel; palea minute, hyaline or 0. Lodicules 2, small, glabrous. Stamens 3. Ovary glabrous; styles terminal, plumose. Caryopsis terete. x= 5, 10 (polyploidy).

Perennial or annual, tufted, sometimes decumbent at base, stoloniferous, sometimes rooting from nodes; culms decumbent, more rarely erect. Leaf blade and sheaths usually bearing gland-tipped hairs, often viscid; ligule a fringe of hairs. Inflorescence a panicle, open or contracted; spikelets solitary, shortly pedicelled to subsessile. Spikelet slightly laterally compressed, disarticulating above glumes; glumes unequal to +/- equal, +/- as long as spikelet, similar, membranous, green or grey, glabrous or hairy, hairs sometimes glandular, lanceolate, 7-11(14)-nerved, awnless. Florets 4-9, bisexual; upper 1 or 2 florets usually reduced and sterile; lemma dorsally rounded, firmer than glumes, 9-nerved, subcoriaceous, dorsally long-villous towards base, usually scabrid, 6-lobed, lobes alternating with 5 straight, scabrid awns from between lobes; callus minute, pointed, hairy; palea longer than lemma, oblong or elliptic-oblong, 2-keeled, with narrow flaps, stiffly ciliate along keels, cilia very often with interspersed glandular-tipped hairs. Lodicules 2, minute, cuneate, truncate or often with apex shallowly bilobed with gland-tipped hairs. Stamens 3. Ovary glabrous; styles distinct, plumose. Caryopsis ellipsoid. x= 9 (polyploidy).

Pedicelled spikelet strongly dorsiventrally compressed, flat; lower glume usually distinctly nerved, male or sterile; lemma awnless. x= 10 (17, 20).

Perennial or annual, tufted, sometimes geniculate. Leaf blade narrowly linear; ligule reduced to a short, fringed membrane. Inflorescence of solitary, paired or digitate, slender, 1-sided spikes; spikelets solitary, sessile. Spikelet strongly laterally compressed, disarticulating above glumes; glumes very unequal, longer than spikelet, similar, membranous, 1-nerved, keeled, acute, mucronate or shortly awned. Florets 1 or 2; 1 bisexual; uppermost floret vestigial but awned; lowest lemma firmer than glumes, chartaceous or cartilaginous, shorter than glumes, ovate-elliptic, keeled, 3-nerved, hairy on nerves, incised, minutely 2-lobed, awned from between lobes; awn long, flexuous, entangled with awns of other spikelets in inflorescence; callus hairy; palea 2-nerved, 2-keeled. Lodicules 2. Stamens 3. Ovary glabrous; styles 2, plumose. Caryopsis (achene) narrowly ellipsoid, laterally compressed; pericarp free.