The World Flora Online

Leaves solitary at the nodes, sometimes crowded at the base of the stem, alternate and 2-rowed, consisting of sheath, ligule and blade; sheaths encircling the culm, with the margins free and overlapping or ± connate, frequently swollen at the base, the shoulders sometimes extended upwards into triangular auricles; ligule adaxial, placed at the junction of sheath and blade, membranous or reduced to a fringe of hairs, rarely absent (very rarely with a similar abaxial structure—the external ligule); blades usually long and narrow, rarely broad, flat or sometimes rolled or terete, parallel-nerved, rarely with transverse connections, usually passing gradually into the sheath, sometimes amplexicaul or with falcate auricles, rarely narrowed into a false petiole or articulated with the sheath Inflorescence made up of spikelets arranged in a panicle, or in spikes or racemes, these either solitary, digitate, or disposed along a central axis; usually terminal, sometimes (especially in Andro-pogoneae) numerous, each inflorescence being subtended by a bladeless sheath (spatheole) and the whole flowering branch system condensed into a leafy false panicle Annual or perennial herbs, rarely shrubs or trees, sometimes with rhizomes or stolons; stems erect, ascending or creeping, usually branched at the base, in perennials with sterile shoots and flowering stems (culms) mixed, in annuals only the latter present; culms cylindrical, rarely flattened, jointed, usually hollow in the internodes, closed at the nodes; branches subtended by a leaf, and with a 2-keeled hyaline leaflet (prophyll) at the base Fruit mostly a caryopsis with thin pericarp adnate to the seed, rarely with free seed, still more rarely a nut or berry; caryopsis commonly combined with various parts of the spikelet, or less often the inflorescence, to form a false fruit; seed with starchy endosperm, an embryo at the base of the abaxial face, and a point or line (hilum) on the base or adaxial face marking the connection between pericarp and seed Flowers usually bisexual, sometimes unisexual, small and inconspicuous; perianth represented by 2, rarely 3, minute hyaline or fleshy scales (lodicules); stamens hypogynous, 1–6, rarely more, usually 3, with delicate filaments and 2-thecous anthers opening by a longitudinal slit or rarely a terminal pore; ovary 1-locular, with 1 anatropous ovule often adnate to the adaxial side of the carpel; styles usually 2, rarely 1 or 3, generally with plumose stigmas Spikelets consisting of bracts distichously arranged along a slender axis (rhachilla); the two lower bracts (glumes) empty; the succeeding 1 to many bracts (lemmas) each enclosing a flower and opposed by a hyaline scale (palea), the whole (lemma, palea and flower) termed a floret; base of spikelet or floret sometimes with a horny prolongation downwards (callus); glumes or lemmas often bearing 1 or more stiff bristles (awns); this basic pattern of spikelet structure consistent throughout the family, though often much modified by reduction, suppression or elaboration of parts Inflorescence made up of spikelets arranged in a panicle, or in spikes or racemes, these either solitary, digitate, or disposed along a central axis; usually terminal, sometimes (especially in Andro-pogoneae) numerous, each inflorescence being subtended by a bladeless sheath (spatheole) and the whole flowering branch system condensed into a leafy false panicle Annual or perennial herbs, rarely shrubs or trees, sometimes with rhizomes or stolons; stems erect, ascending or creeping, usually branched at the base, in perennials with sterile shoots and flowering stems (culms) mixed, in annuals only the latter present; culms cylindrical, rarely flattened, jointed, usually hollow in the internodes, closed at the nodes; branches subtended by a leaf, and with a 2-keeled hyaline leaflet (prophyll) at the base Fruit mostly a caryopsis with thin pericarp adnate to the seed, rarely with free seed, still more rarely a nut or berry; caryopsis commonly combined with various parts of the spikelet, or less often the inflorescence, to form a false fruit; seed with starchy endosperm, an embryo at the base of the abaxial face, and a point or line (hilum) on the base or adaxial face marking the connection between pericarp and seed Flowers usually bisexual, sometimes unisexual, small and inconspicuous; perianth represented by 2, rarely 3, minute hyaline or fleshy scales (lodicules); stamens hypogynous, 1–6, rarely more, usually 3, with delicate filaments and 2-thecous anthers opening by a longitudinal slit or rarely a terminal pore; ovary 1-locular, with 1 anatropous ovule often adnate to the adaxial side of the carpel; styles usually 2, rarely 1 or 3, generally with plumose stigmas Spikelets consisting of bracts distichously arranged along a slender axis (rhachilla); the two lower bracts (glumes) empty; the succeeding 1 to many bracts (lemmas) each enclosing a flower and opposed by a hyaline scale (palea), the whole (lemma, palea and flower) termed a floret; base of spikelet or floret sometimes with a horny prolongation downwards (callus); glumes or lemmas often bearing 1 or more stiff bristles (awns); this basic pattern of spikelet structure consistent throughout the family, though often much modified by reduction, suppression or elaboration of parts

Leaf-sheaths clasping the culm, usually rather tight, ribbed or smooth, with the margins free or connate to a varying degree and often overlapping, often with a pair of auricles on either side of the mouth Leaves solitary, alternate in 2 ranks, all crowded around the base of the stem or/and spaced along the culm, in most cases consisting of sheath, ligule and lamina (tab. 1) Culms usually cylindrical, very seldom compressed, jointed with the nodes solid, the internodes hollow or sometimes solid, erect, ascending or prostrate, sometimes rooting at the nodes, branched or simple; branches at the base with a hyaline 2-keeled prophyll Mostly annual or perennial herbs, rarely shrubs or trees (Bambuseae), often with rhizomes, sometimes stoloniferous Fruit 1-seeded, usually a caryopsis, with the pericarp adnate to the seed or sometimes free (rarely fleshy) Spikelets (see pl. tab. 1) usually consisting of 2 (rarely more) glumes and 1 to several lemmas distichously arranged along a rhachilla; each lemma is opposed by a usually thinly membranous palea; enclosed between lemma and palea is the flower (the entire unit is termed a floret); glumes and/or lemmas often awned; florets, and sometimes the entire spikelet, with a basal indurated callus which is either blunt or acute; flower usually hermaphrodite, sometimes unisexual, rather small, consisting of 2-3 minute lodicules (representing the perianth) stamens and ovary; stamens hypogynous, usually 3, sometimes less, rarely 6 or more, with the 2-thecous anthers either opening lengthwise or with a terminal pore; ovary 1-locular; styles 2, rarely 1 or 3; stigmas usually plumose Inflorescence usually terminal on the culms, rarely axillary, consisting of numerous spikelets arranged in spikes, or in racemes or in a panicle; the spikes or racemes either solitary or more often arranged along a common axis, sometimes digitate, often (Andropogoneae) subtended by a spatheole (sheath without lamina) and often branched, thus forming a complicated pseudo-panicle in which frequently a sessile spikelet is paired with a pedicelled one Leaf-laminae usually linear or linear-lanceolate, more rarely ovate or oblong, rather narrow, generally parallel-nerved but in a few instances tessellate, expanded, plicate, or sometimes rolled, thus appearing to be terete, often filiform, rarely amplexicaul or with a sagittate base, occasionally with the very base contracted into a pseudo-petiole, very rarely articulated with the sheath Ligule situated transversely at the junction of sheath and lamina, adaxial, membranous or chartaceous, often reduced to a hairy rim, rarely completely absent in some genera Leaves solitary, alternate in 2 ranks, all crowded around the base of the stem or/and spaced along the culm, in most cases consisting of sheath, ligule and lamina (tab. 1) Culms usually cylindrical, very seldom compressed, jointed with the nodes solid, the internodes hollow or sometimes solid, erect, ascending or prostrate, sometimes rooting at the nodes, branched or simple; branches at the base with a hyaline 2-keeled prophyll Mostly annual or perennial herbs, rarely shrubs or trees (Bambuseae), often with rhizomes, sometimes stoloniferous Fruit 1-seeded, usually a caryopsis, with the pericarp adnate to the seed or sometimes free (rarely fleshy) Spikelets (see pl. tab. 1) usually consisting of 2 (rarely more) glumes and 1 to several lemmas distichously arranged along a rhachilla; each lemma is opposed by a usually thinly membranous palea; enclosed between lemma and palea is the flower (the entire unit is termed a floret); glumes and/or lemmas often awned; florets, and sometimes the entire spikelet, with a basal indurated callus which is either blunt or acute; flower usually hermaphrodite, sometimes unisexual, rather small, consisting of 2-3 minute lodicules (representing the perianth) stamens and ovary; stamens hypogynous, usually 3, sometimes less, rarely 6 or more, with the 2-thecous anthers either opening lengthwise or with a terminal pore; ovary 1-locular; styles 2, rarely 1 or 3; stigmas usually plumose Inflorescence usually terminal on the culms, rarely axillary, consisting of numerous spikelets arranged in spikes, or in racemes or in a panicle; the spikes or racemes either solitary or more often arranged along a common axis, sometimes digitate, often (Andropogoneae) subtended by a spatheole (sheath without lamina) and often branched, thus forming a complicated pseudo-panicle in which frequently a sessile spikelet is paired with a pedicelled one Leaf-laminae usually linear or linear-lanceolate, more rarely ovate or oblong, rather narrow, generally parallel-nerved but in a few instances tessellate, expanded, plicate, or sometimes rolled, thus appearing to be terete, often filiform, rarely amplexicaul or with a sagittate base, occasionally with the very base contracted into a pseudo-petiole, very rarely articulated with the sheath Ligule situated transversely at the junction of sheath and lamina, adaxial, membranous or chartaceous, often reduced to a hairy rim, rarely completely absent in some genera

Fls perfect or sometimes unisexual, 1–many in distichously organized spikelets, each spikelet typically with a pair of subopposite small bracts (glumes) at the base and one to several or many florets alternating on opposite sides of an often zigzag axis (the rachilla) above the glumes; each floret typically consisting of a pair of subopposite enclosing or subtending scales (the lemma and palea), two or three much smaller scales (the lodicules) above these, and the stamens and pistil; midvein of the lemma often excurrent as a dorsal or terminal awn; palea placed with its back to the rachilla, typically with 2 main veins, generally enfolded by the lemma, rarely suppressed; lowest floret sometimes represented by an empty or staminate, glume-like sterile lemma, the spikelet then usually with a single perfect terminal fl; stamens most often 3, sometimes 6, rarely more, seldom only 1 or 2, typically exserted at anthesis and the plants wind-pollinated, but sometimes included and the plants selfed; anthers elongate, basifixed but so deeply sagittate as to appear versatile; ovary superior, unilocular, bicarpellate or less often tricarpellate, accordingly with 2 or 3 often large and feathery stigmas; ovule solitary, subapical to basilateral, orthotropous to hemitropous or almost anatropous; fr, called a caryopsis or grain, usually tightly enclosed by the persistent lemma and palea, indehiscent, usually dry, the seed-coat usually adnate to the pericarp; embryo basilateral, peripheral to the endosperm, complex in structure, with an enlarged lateral cotyledon (the scutellum); herbs or seldom somewhat woody plants, without secondary thickening, the culms (flowering stems) terete (seldom flattened) and usually with hollow internodes; lvs distichously or rarely spirally arranged, but not 3-ranked, with a usually open sheath and a parallel-veined, typically narrow and elongate blade, often with a pair of small auricles at the base of the blade, and commonly with a membranous ligule adaxially at the juncture of sheath and blade, or the ligule sometimes composed of hairs, or wanting; spikelets arranged in a determinate or mixed secondary infl that most commonly has the form of a panicle but is sometimes spike-like or raceme-like. 600/10,000. The term rame is here used for an unbranched infl that bears both sessile and pedicellate spikelets. The arrangement of genera of grasses into subfamilies and tribes is in a state of flux. Many of the characters now being used are microscopic. The key to genera here presented (largely written by Richard Pohl) is artificial. The sequence of genera in the text is based mainly on that of Clayton and Renvoize, Genera Graminum, 1986. Sclerochloa dura (L.) P. Beauv., a native of s. Europe, is intr. at scattered stations in w. U.S. and in O., Mich., Ind., Ill., and Mo., and may be expected elsewhere in our range. Not very closely related to any of our genera, it falls between the first two alternatives of Group IV in the key, having only one obvious spike, as in the second alternative, but having the spikelets secundly arranged along two sides of the trigonous rachis, as in the first alternative. It is a tufted low annual, mostly under 2 dm, with broad, rounded, prominently 5-nerved lemmas. The persistent style-base forms a short beak on the grain.

Annual or perennial herbs, or tall woody bamboos. Flowering stems (culms) jointed, internodes hollow or solid; branches arising singly from nodes and subtended by a leaf sheath and 2-keeled prophyll, often fascicled in bamboos. Leaves arranged alternately in 2 ranks, differentiated into sheath, blade, and an adaxial erect appendage at sheath/blade junction (ligule); leaf sheath surrounding and supporting culm-internode, split to base or infrequently tubular with partially or completely fused margins, modified with reduced blade in bamboos (culm sheaths); leaf blades divergent, usually long, narrow and flat, but varying from inrolled and filiform to ovate, veins parallel, sometimes with cross-connecting veinlets (especially in bamboos); ligule membranous or a line of hairs. Inflorescence terminal or axillary, an open, contracted, or spikelike panicle, or composed of lax to spikelike racemes arranged along an elongate central axis, or digitate, paired, or occasionally solitary; axillary inflorescences often many, subtended by spatheoles (specialized bladeless leaf sheaths) and gathered into a leafy compound panicle; spikelets often aggregated into complex clusters in bamboos. Spikelets composed of distichous bracts arranged along a slender axis (rachilla); typically 2 lowest bracts (glumes) empty, subtending 1 to many florets; glumes often poorly differentiated from accompanying bracts in bamboos. Florets composed of 2 opposing bracts enclosing a single small flower, outer bract (lemma) clasping the more delicate, usually 2-keeled inner bract (palea); base of floret often with thickened prolongation articulated with rachilla (callus); lemma often with apical or dorsal bristle (awn), glumes also sometimes awned. Flowers bisexual or unisexual; lodicules (small scales representing perianth) 2, rarely 3 or absent, 3 to many in bamboos, hyaline or fleshy; stamens 3 rarely 1, 2, 6, or more in some bamboos, hypogynous, filaments capillary, anthers versatile; ovary 1-celled, styles (1 or)2(rarely 3), free or united at base, topped by feathery stigmas, exserted from sides or apex of floret. Fruit normally a dry indehiscent caryopsis with thin pericarp firmly adherent to seed, pericarp rarely free, fleshy in some bamboos; embryo small or large; hilum punctate to linear.

Leaves solitary at the nodes, sometimes crowded at the base of the stem, alternate and 2-rowed, consisting of sheath, ligule and blade (fig. 1, p. 3); sheaths encircling the culm, with the margins free and overlapping or ± connate, frequently swollen at the base, the shoulders sometimes extended upwards into triangular auricles; ligule adaxial, placed at the junction of sheath and blade, membranous or reduced to a fringe of hairs, rarely absent (very rarely with a similar abaxial structure—the external ligule); blades usually long and narrow, rarely broad, flat or sometimes rolled or terete, parallel-nerved, rarely with transverse connections, usually passing gradually into the sheath, sometimes amplexicaul or with falcate auricles, rarely narrowed into a false petiole or articulated with the sheath Fruit mostly a caryopsis with thin pericarp adnate to the seed, rarely with free seed, still more rarely a nut or berry; caryopsis commonly combined with various parts of the spikelet, or less often the inflorescence, to form a false fruit; seed with starchy endosperm, an embryo at the base of the abaxial face, and a point or line (hilum) on the base or adaxial face marking the connection between pericarp and seed Annual or perennial herbs, rarely shrubs or trees, sometimes with rhizomes or stolons; stems erect, ascending or creeping, usually branched at the base, in perennials with sterile shoots and flowering stems (culms) mixed, in annuals only the latter present; culms cylindrical, rarely flattened, jointed, usually hollow in the internodes, closed at the nodes; branches subtended by a leaf, and with a 2-keeled hyaline leaflet (prophyll) at the base Flowers usually hermaphrodite, sometimes unisexual, small and inconspicuous; perianth represented by 2, rarely 3, minute hyaline or fleshy scales (lodicules); stamens hypogynous, 1–6, rarely more, usually 3, with delicate filaments and 2-thecous anthers opening by a longitudinal slit or rarely a terminal pore; ovary 1-locular, with 1 anatropous ovule often adnate to the adaxial side of the carpel; styles usually 2, rarely 1 or 3, generally with plumose stigmas Inflorescences made up of spikelets arranged in a panicle, or in spikes or racemes, these either solitary, digitate, or disposed along a central axis, usually terminal, sometimes (especially in Andropogoneae) numerous, each inflorescence being subtended by a bladeless sheath (spatheole) and the whole flowering branch system condensed into a leafy false panicle Spikelets (fig. 1) consisting of bracts distichously arranged along a slender axis (rhachilla); the 2 lower bracts (glumes) empty; the succeeding 1 to many bracts (lemmas) each enclosing a flower and opposed by a hyaline scale (palea), the whole (lemma, palea and flower) termed a floret; base of spikelet or floret sometimes with a horny prolongation downwards (callus); glumes or lemmas often bearing 1 or more stiff bristles (awns); this basic pattern of spikelet structure consistent throughout the family, though often much modified by reduction, suppression or elaboration of parts Fruit mostly a caryopsis with thin pericarp adnate to the seed, rarely with free seed, still more rarely a nut or berry; caryopsis commonly combined with various parts of the spikelet, or less often the inflorescence, to form a false fruit; seed with starchy endosperm, an embryo at the base of the abaxial face, and a point or line (hilum) on the base or adaxial face marking the connection between pericarp and seed Annual or perennial herbs, rarely shrubs or trees, sometimes with rhizomes or stolons; stems erect, ascending or creeping, usually branched at the base, in perennials with sterile shoots and flowering stems (culms) mixed, in annuals only the latter present; culms cylindrical, rarely flattened, jointed, usually hollow in the internodes, closed at the nodes; branches subtended by a leaf, and with a 2-keeled hyaline leaflet (prophyll) at the base Flowers usually hermaphrodite, sometimes unisexual, small and inconspicuous; perianth represented by 2, rarely 3, minute hyaline or fleshy scales (lodicules); stamens hypogynous, 1–6, rarely more, usually 3, with delicate filaments and 2-thecous anthers opening by a longitudinal slit or rarely a terminal pore; ovary 1-locular, with 1 anatropous ovule often adnate to the adaxial side of the carpel; styles usually 2, rarely 1 or 3, generally with plumose stigmas Inflorescences made up of spikelets arranged in a panicle, or in spikes or racemes, these either solitary, digitate, or disposed along a central axis, usually terminal, sometimes (especially in Andropogoneae) numerous, each inflorescence being subtended by a bladeless sheath (spatheole) and the whole flowering branch system condensed into a leafy false panicle Spikelets (fig. 1) consisting of bracts distichously arranged along a slender axis (rhachilla); the 2 lower bracts (glumes) empty; the succeeding 1 to many bracts (lemmas) each enclosing a flower and opposed by a hyaline scale (palea), the whole (lemma, palea and flower) termed a floret; base of spikelet or floret sometimes with a horny prolongation downwards (callus); glumes or lemmas often bearing 1 or more stiff bristles (awns); this basic pattern of spikelet structure consistent throughout the family, though often much modified by reduction, suppression or elaboration of parts