POACEAE  

Annual or rarely perennial, tufted, often hygrophilous. Leaf blade linear to linear-lanceolate, expanded; ligule an unfringed membrane. Inflorescence a panicle, contracted, dense or much branched and divaricate, usually rigid, always much longer than broad, branches in pseudowhorls on a strongly developed central axis; spikelets solitary, pedicelled. Spikelet 1-3 mm long, laterally compressed, disarticulating above glumes and between florets; glumes unequal to +/- equal, shorter than spikelets, ovate to lanceolate, membranous, often subhyaline, keeled, 1-nerved, awnless. Florets 2-10, bisexual, sometimes uppermost floret rudimentary; lemma 0.5-1.0 mm long, similar to firmer in texture to glumes, usually translucent or thinly coriaceous, glabrous, strongly keeled, often depressed between keels, 3-nerved, nerves distinct, rounded, emarginate or acute or sometimes somewhat erose, awnless; callus short, truncate, glabrous; palea subequal to lemma, membranous, 2-keeled, nerves strongly developed in lower part of keels, apex truncate or rounded, or 3-lobed. Lodicules 2, truncate. Stamens 2. Ovary glabrous; styles terminal, plumose. x= 10.

Perennial, rarely annual, tufted. Leaf blade linear or lanceolate-linear, expanded; ligule a fringe of hairs. Inflorescence an open or contracted panicle; spikelets paired, rarely in threes or solitary, pedicelled, pedicels free. Spikelet 4-20 mm long, laterally compressed, disarticulating above glumes; glumes very unequal, scarious-membranous to chartaceous, rarely thinly coriaceous, 3-5-nerved, glabrous, dissimilar; lower glume not more than half the length of upper; upper glume lanceolate, ovate, oblong. Florets 2; lower floret male with lemma similar to upper glume, as long as or slightly shorter than spikelet, (3)5-9-nerved, awnless; palea membranous, narrow, 2-keeled with keels very narrowly winged; upper floret bisexual, lemma 7-9-nerved, similar in texture to glumes, hairy, hairs in 2-8 distinct tufts or fringes or tufts mixed with dispersed hairs, deeply 2-lobed, lobes acute, sometimes produced into fine scaberulous awns, awned from between lobes; awn geniculate, twisted below bend; callus short, square to oblong, obtuse; palea similar to that of lower floret but keels firmer and usually with wider wings; wings expanded into +/- triangular or clavate appendages. Lodicules 2, cuneate, fleshy. Stamens 3. Ovary glabrous; styles distinct, plumose above. x= 12 (1 report, polyploidy).

Perennial, tufted, rhizomatous (rhizome often oblique). Leaf blade linear to linear-lanceolate, expanded or rolled; sheaths keeled, compressed; ligule an unfringed membrane. Inflorescence an open or contracted panicle, lobed, branches secund; spikelets crowded in dense shortly pedicelled clusters at ends of short main branches. Spikelet 5-9 mm long, strongly laterally compressed, disarticulating above glumes; glumes +/- equal or unequal, similar, shorter than spikelet, lanceolate to ovate, rigid, membranous, 3-nerved, strongly keeled, glabrous or hairy on keel, acuminate to mucronate or awned. Florets 2-5(7), bisexual; uppermost floret often sterile; lemma firmer in texture than glumes, lanceolate-oblong, 5-nerved, strongly keeled, keels hairy or scabrid, shortly awned; awn straight, shorter than body of lemma; callus short, glabrous; palea slightly shorter than lemma, 2-keeled. Lodicules 2, bilobed, glabrous. Stamens 3. Ovary glabrous; styles plumose. Caryopsis ovoid, tightly enclosed by hardened lemma and palea. x= 7 (polyploidy, B-chromosomes).

Perennial, stoloniferous or rhizomatous, often mat-forming. Leaf blade linear, flat or folded; ligule a fringed membrane or a fringe of hairs. Inflorescence of 1-5 closely spaced 1-sided spikes, in pairs, digitate or subdigitate; rachis flattened; spikelets solitary, sessile. Spikelet 2.0-3.5 mm long, strongly laterally compressed, disarticulating above glumes; glumes +/- equal to unequal, similar, narrow, shorter than or rarely as long as spikelet, acute, keeled, sometimes scabrid on keel, awnless, 1-nerved, rarely upper glume 3-nerved. Floret 1, bisexual, with or without a rachilla extension, rarely bearing a second floret which is usually small and reduced, rarely well developed; lemma similar to firmer in texture to glumes, obtuse, 1-4-nerved, keeled, keel winged or wingless, hairy on keel and often on margins, flanks usually glabrous, awnless; callus glabrous; palea as long as or shorter than lemma, obtuse or subacute, membranous, 2-keeled. Lodicules 2, minute, obovate-cuneate, glabrous. Stamens 3. Ovary glabrous; styles distinct, plumose above. Caryopsis ellipsoid, laterally compressed. x= 9, 10 (polyploidy).

Perennial, rarely annual, tufted, wiry. Leaf blade linear, expanded or rolled; ligule a very short fringed membrane. Inflorescence a solitary, terminal, often strongly falcate, 1-sided spike; spikelets alternately biseriate along midrib of flattened rachis; spikelet solitary, sessile. Spikelet laterally compressed, disarticulating above glumes, not between florets; glumes unequal, dissimilar, tubercled on nerves; lower glume membranous, +/- half as long as upper, 1-nerved, acute, keeled, with awn-point; upper glume longer than lemma, lanceolate, flat or rounded obliquely, acuminate, 2- or 3-nerved, awned from back below apex with oblique dorsal awn. Florets 3-5, lower 2 florets male or sterile, third floret bisexual, uppermost floret rudimentary or male; lemma less firm in texture than glumes, dissimilar, oblong, entire, obtuse, 3-nerved, hairy or uppermost glabrous, awned from just below apex; awn straight; palea shorter than lemma, 2-keeled, 2-nerved. Lodicules 2, quadrate-cuneate or ovate, delicate. Stamens 3 in bisexual floret, 2 in male floret. Ovary glabrous; styles distinct, plumose above. Caryopsis ellipsoid. x= 9 (high polyploidy).