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| 1 Leaves peltate. |
| ..2 Leaf blades oval in shape, ca. 1.5-2× as long as wide, at maturity floating on the water’s surface; underwater portions of fresh plant coated in transparent mucilage |
| ..2 Leaf blades orbicular in shape, ca. 1× as long as wide, at maturity floating on the water’s surface, emersed, or submersed; underwater portions of fresh plant not mucilaginous (though possibly with green algae, etc.). |
| ....3 Leaves small, < 8 cm in diameter, at maturity emersed or submersed |
| ....3 Leaves large, > 20 cm in diameter, at maturity floating on the water’s surface or emersed |
| 1 Leaves not peltate, the petiole attached at a cuneate, cordate, or sagittate base. |
| ......4 Leaf blades cuneate, rounded, or truncate at the base. |
| ........5 Basal leaves lanceolate, 3-6 mm long |
| ........5 Basal leaves variously shaped, > 10 mm long. |
| ..........6 Main veins palmate from the leaf base and also diverging from the midvein, the secondary and tertiary veins then reticulating; inflorescence a spike; [Eudicots] |
| ..........6 Main veins either parallel or palmate from the leaf base with cross-veins at nearly right angles to the main veins; inflorescence either a diffuse raceme or panicle of white flowers, or a linear spadix of tightly packed golden-yellow flowers; [Monocots]. |
| ............ 7 Inflorescence diffuse, a raceme or panicle with whorled branches or pedicels, the flowers widely spaced and white; leaves green, “wettable” |
| ............ 7 Inflorescence tightly packed with flowers, an elongate, golden yellow spadix; leaves blue-green, “unwettable” |
| ......4 Leaf blades cordate or sagittate at the base. |
| ............ ..8 Leaf blades sagittate, the two lobes distinctly acute; leaf apex acute; leaf blade 1.3-3× as long as wide |
| ............ ..8 Leaf blades cordate, the two lobes rounded or sub-acute; leaf apex rounded or apiculate; leaf blade 0.8-8× as long as wide. |
| ............ ....9 Leaf blade margins serrate, dentate, and/or incised |
| ............ ....9 Leaf blade margins entire or obscurely crenate. |
| ............ ......10 Flowers 4-5-merous (sepals 4-5, petals 4-5, stamens 4-5); [Eudicots] |
| ............ ........11 Leaves emersed or submersed, on stout, stiff petioles (the submersed and winter leaves cuneate-based and lanceolate); flowers 4-merous (sepals 4, petals 4, stamens 4); inflorescence a spike |
| ............ ........11 Leaves floating, on slender, flexuous petioles (all leaves cordate-based); flowers 5-merous (sepals 5, petals 5, stamens 5); inflorescence an umbel |
| ............ ......10 Flowers 3-merous or many (>5-) -merous; [Basal Angiosperms or Monocots]. |
| ............ ..........12 Perianth parts numerous (usually showing differentiation into sepals and petals, though often with some intergradation), borne in a spiral; stamens numerous; leaves usually > 10 cm long or > 10 cm wide, or both (a few northern species of Nymphaea with leaves as small as 2.5 cm × 2.5 cm); [Basal Angiosperms] |
| ............ ..........12 Perianth parts 3-6 (either differentiated or not into sepals and petals); stamens either 3, or 9-12 (-18), or >20; leaves 1-10 cm long, 1-10 cm wide; [Monocots]. |
| ............ ............ 13 Perianth strongly differentiated, the 3 sepals green, leathery, and persistent, the 3 petals yellow or white, delicate, deciduous; stamens 20 or more |
| ............ ............ 13 Perianth not strongle differentiated, the sepals petaloid and similar in texture and color to the petals; stamens 10 or fewer. |
............ ............ ..14 Flowers unisexual, white, the sepals and petals separate; stamens 3, 6, 9, 12, 15, or 18; leaves either with a central area of spongiform cells (most easily seen on the lower leaf surface) ( Limnobium), or without spongiform cells ( Ottelia) |
| ............ ............ ..14 Flowers bisexual, white to blue, the perianth segments united below into a perianth tube 3-45 mm long; stamens 3; leaves lacking a central area of spongiform cells |
| 1 Leaves whorled, most nodes with 3 or more leaves. |
| ..2 Leaves strongly toothed to pectinate |
| ..2 Leaves entire or finely toothed. |
| ....3 Leaves tipped by a callus (visible at 10× magnification); leaf margins entire; flowers many, grouped in a terminal involucrate head; [Eudicots] |
....3 Leaves not callus-tipped; leaf margins finely toothed or at least with conical protrusions remaining from the disintegration of better-developed deciduous teeth; flowers solitary on elongate, flexuous stalks; [Monocots] |
| 1 Leaves opposite, no nodes with 3 or more leaves. |
| ......4 Cauline leaves in 1 pair |
| ......4 Cauline leaves in 2-many nodes. |
| ........5 Leaves in 2-3 pairs, appearing verticillate; plants of marine waters; [of FL, MS, LA and southward] |
| ........5 Leaves along stem at 2-many nodes; plants of fresh to brackish waters; [collectively widespread]. |
| ..........6 Flowers 3-merous; [Monocots]. |
| ............ 7 Leaf margins (or at least leaf sheaths) serrate or minutely spiny; fruits sessile, entire; leaves 5-15× as long as wide |
| ............ 7 Leaf margins (including sheaths) entire; fruit stalked, dentate on one side; leaves >20× as long as wide |
| ..........6 Flowers 4- or 5-merous; [Eudicots]. |
| ............ ..8 Leaves 1-12 cm long; flowers borne in axillary or terminal spikes or clusters |
| ............ ..8 Leaves 0.5-3 (-5) cm long; flowers solitary, axillary. |
| ............ ....9 Carpels 4-5, separate; fruit an aggregate of follicles; leaves succulent |
| ............ ....9 Carpels 2-5, fused; fruit capsular (variously dehiscent); leaves thin in texture or somewhat succulent (e.g. Bacopa in PLANTAGINACEAE). |
| ............ ......10 Leaves dimorphic, the terminal leaves usually spatulate (strongly expanded towards the apex); corolla absent; stamen 1 |
| ............ ......10 Leaves monomorphic, obovate, oblanceolate, or parallel-margined; corolla present (absent in Didiplis in LYTHRACEAE); stamens 2-6. |
| ............ ........11 Flower radially symmetrical, 3-4-merous; petals absent or separate |
| ............ ..........12 Stems lacking ridges running down from leaf bases |
| ............ ..........12 Stems with ridges running down from leaf bases |
| ............ ........11 Flower bilaterally symmetrical, 4-5-merous; petals present, fused at least basally, forming a tube. |
| ............ ............ 13 Corolla 4-merous |
| ............ ............ 13 Corolla 5-merous |
| 1 Leaves compound. |
| ..2 Plants herbaceous; leaves palmately 3-foliolate or pedately compound |
| ..2 Plants woody; leaves either palmately divided or pinnately compound into > 20 segments |
| 1 Leaves simple. |
| ....3 Leaves opposite or whorled, cauline. |
| ......4 Leaves opposite; flowers bilaterally symmetrical |
| ......4 Leaves whorled; flowers radially or bilaterally symmetrical. |
| ........5 Plant with 2 or more leaf-bearing nodes (all nodes whorled or some alternate). |
| ..........6 Leaves broad, < 2× as long as wide, cordate at the base; flowers unisexual and plants dioecious |
| ..........6 Leaves lanceolate, oblanceolate or narrowly elliptic, > 4× as long as wide, cuneate at the base; flowers bisexual and plants hermaphroditic |
| ........5 Plant with a single leaf-bearing node. |
| ............ 7 Leaves in whorls of 3 leaves |
| ............ 7 Leaves in whorls of 5 or more leaves. |
| ............ ..8 Stem floccose, wiry (and at maturity with a second smaller whorl with usually 3 leaves subtending the flowers); flowers radially symmetrical |
| ............ ..8 Stem glabrous, fleshy, never with a second whorl; flowers bilaterally symmetrical |
| ....3 Leaves alternate, either cauline or basal. |
| ............ ....9 Inflorescence a spadix (a dense spike of hundreds of flowers, the rachis thickened and somewhat fleshy) subtended by a spathe (a green, white, orange, yellowish-green, or maroon bract) (spathe missing in Orontium) |
| ............ ....9 Inflorescence otherwise, a raceme, panicle, cyme, umbel, spike, etc., the flowers arrayed in a more diffuse manner, the central rachis not thickened, the inflorescence subtended or not by green or scarious spathes. |
| ............ ......10 Flowers bilaterally symmetrical or asymmetrical; fertile stamens 1 or 2 (or 5 in MUSACEAE), often with several staminodes present as well; tepals 6. |
| ............ ........11 Leaf venation parallel; leaves various in size and shape, if > 3 dm long, then < 1 dm wide; perianth often differentiated into a lip and 5 petaloid tepals |
| ............ ........11 Leaf venation prominently penni-parallel; leaves large, at least some on a plant with blade > 2 dm long. |
| ............ ..........12 Fertile stamens 5-6; leaf blades 6-30 dm long |
| ............ ..........12 Fertile stamen 1; leaf blades 0.5-7 dm long. |
| ............ ............ 13 Leaves spirally arranged. |
| ............ ............ ..14 Leaves lacking ligules; ovary and fruit with warty excrescences |
| ............ ............ ..14 Leaves with 2 stipule-like ligules; ovary and fruit smooth |
| ............ ............ 13 Leaves 2-ranked. |
| ............ ............ ....15 Leaves jointed and swollen at the summit of the petiole |
| ............ ............ ....15 Leaves neither jointed not swollen at the summit of the petiole |
| ............ ......10 Flowers radially symmetrical (weakly to strongly bilaterally symmetrical in PONTEDERIACEAE); stamens 6 (rarely 3, 4, 5, 9, 12, 15, or 18); tepals usually 6 (rarely 3 or 4), when 6, either undifferentiated (6 or 4 tepals) or differentiated into 3 petals and 3 sepals. |
| ............ ............ ......16 Inflorescence subtended by spathes (well-developed green or scarious bracts). |
| ............ ............ ........17 Perianth not differentiated, consisting of 6 similarly colored and shaped tepals; flowers strongly to slightly bilaterally symmetrical; inflorescence lacking well-developed spathaceous bracts |
| ............ ............ ........17 Perianth differentiated into green sepals and more brightly colored petals; flowers radially symmetrical (or weakly bilaterally symmetrical, as in some Commelina). |
| ............ ............ ..........18 Ovary superior; fruit a capsule; stamens 6; [plants mainly of uplands (Murdannia and sometimes Commelina of wetlands)] |
............ ............ ..........18 Ovary inferior; fruit a berry; stamens 3, 6, 9, 12, 15, or 18; [plants of wetlands] |
| ............ ............ ......16 Inflorescence not subtended by spathes, though individual small green bracts sometimes subtending individual flowers. |
| ............ ............ ............ 19 Gynoecium of 2 or more pistils (6 in Butomus); fruit achenes or follicles; inflorescence a raceme or panicle with branching in whorls of 3 OR a bracteate umbel; [wetland plants]. |
| ............ ............ ............ ..20 Flowers consisting of white petals and green sepals, with 1-many stamens and 3-many carpels (but not consistently with 9 stamens and 6 carpels); inflorescence a raceme or panicle in whorls of 3, branched; leaf blades flat or terete |
| ............ ............ ............ ..20 Flowers consisting of pink petals and green-pink sepals, usually with 9 stamens and 6 carpels; inflorescence an umbel; leaf blades triquetrous in cross-section |
| ............ ............ ............ 19 Gynoecium of 1 pistil; fruit simple, a capsule or berry; inflorescence various, terminal or axillary, but if a raceme or panicle, not with branching in whorls of 3; [upland (or very rarely wetland) plants]. |
| ............ ............ ............ ....21 Leaves basal or basally disposed. |
| ............ ............ ............ ......22 Leaves 2 (rarely 3 in Convallaria in RUSCACEAE). |
| ............ ............ ............ ........23 Inflorescence a raceme; fruit a berry; tepals united, the perianth urceolate |
| ............ ............ ............ ........23 Inflorescence an umbel or a solitary flower; fruit a capsule; tepals separate or basally fused. |
| ............ ............ ............ ..........24 Flowers in an umbel, white; fresh plants with oniony odor |
| ............ ............ ............ ..........24 Flowers solitary, white or yellow; fresh plants without strong odor |
| ............ ............ ............ ......22 Leaves 4 or more. |
| ............ ............ ............ ............ 25 Inflorescence a terminal umbel; fruit a blue or black berry; tepals white or yellow; flowers bisexual |
| ............ ............ ............ ............ 25 Inflorescence a terminal raceme or panicle; fruit a capsule; tepals white, green, yellowish, or pink; flowers either bisexual (Helonias in HELONIADACEAE), or unisexual and primarily on different plants (dioecious) (Chamaelirium in CHIONOGRAPHIDACEAE), or a mix of bisexual and unisexual staminate flowers (Veratrum in MELANTHIACEAE) |
| ............ ............ ............ ............ ..26 Inflorescences bracteate, with bracts subtending individual pedicels and (if they are present) branches of the inflorescence; tepals white, greenish-white, or cream |
| ............ ............ ............ ............ ..26 Inflorescence ebracteate, lacking bracts subtending pedicels; flowers bisexual (Helonias) or predominantly unisexual and on different plants (dioecious) (Chamaelirium); tepals pink (Helonias) or white to cream (Chamaelirium). |
| ............ ............ ............ ............ ....27 Flowers white to cream; plants dioecious (individual plants either male or female, with all male flowers or all female flowers) |
| ............ ............ ............ ............ ....27 Flowers pink; plants hermaphroditic (individual flowers bisexual) |
| ............ ............ ............ ....21 Leaves cauline. |
| ............ ............ ............ ............ ......28 Leaves both cordate/subcordate (rarely merely rounded at the base) and obviously petiolate. |
| ............ ............ ............ ............ ........29 Inflorescence an axillary many-flowered umbel; fruit a berry; axillary tendrils often present (absent in some species) |
| ............ ............ ............ ............ ........29 Inflorescence an axillary solitary flower, a few-flowered cyme, or a panicle; fruit a capsule (winged in Dioscorea, unwinged in Croomia); axillary tendrils never present (plant not climbing, or climbing by twining). |
| ............ ............ ............ ............ ..........30 Tepals 6; stamens 6; flowers unisexual (and generally on separate plants, therefore dioecious); inflorescence of a solitary flowers or a panicle; ovary inferior; [widespread in our area] |
| ............ ............ ............ ............ ..........30 Tepals 4 (-5); stamens 4 (-5); flowers bisexual; ovary superior; [AL and adjacent GA, FL, and perhaps LA] |
| ............ ............ ............ ............ ......28 Leaves not both cordate/subcordate and petiolate (some with cordate clasping or perfoliate leaf bases). {add [Smilax] SMILACACEAE below} |
| ............ ............ ............ ............ ............ 31 Leaves alternate and in whorls at some nodes; flowers orange; tepals > 5 cm long; inflorescence a terminal umbel or single flower |
| ............ ............ ............ ............ ............ 31 Leaves strictly alternate; flowers yellow, white, pink, greenish, or maroon; tepals < 5 cm long; inflorescence either a terminal cluster, raceme, panicle or umbel, or an axillary raceme, cluster or solitary flower. |
| ............ ............ ............ ............ ............ ..32 Inflorescence a terminal umbel; flowers slightly zygomorphic, reddish, the tepals 3.5-4.5 cm long |
| ............ ............ ............ ............ ............ ..32 Inflorescence either a terminal cluster, raceme, or panicle, or an axillary raceme, cluster or solitary flower; flowers actinomorphic, variously colored (most white or yellow), the tepals < 3.5 cm long (except Uvularia grandiflora). |
| ............ ............ ............ ............ ............ ....33 Leaves arrayed spirally around an erect, unbranched stem; fruit a septicidal capsule; flowers a mixture of bisexual and unisexual (staminate) on a plant; perianth white, greenish white, or maroon. |
| ............ ............ ............ ............ ............ ......34 Leaves basally disposed; leaves not at all to slightly plicate, 1-14 cm wide; tepals glabrous, 4-9 mm long, 1-3 mm wide (3-5 mm wide in M. hybridum), with either conspicuous (M. hybridum) or diffuse (M. parviflorum and M. woodii) glands; filaments fused to the basal claw of the tepal |
| ............ ............ ............ ............ ............ ......34 Leaves cauline; leaves strongly plicate, 6-15 cm wide; tepals pubescent, 8-13 mm long, 3-5 mm wide, with a conspicuous pair of glands near the base of the tepal blade (these sometimes more or less fused); filaments free from the tepals |
| ............ ............ ............ ............ ............ ....33 Leaves arrayed distichously (2 ranked) along an arching, unbranched or dichotomously (Y-forking) branched stem; fruit a berry or loculicidal capsule; flowers all bisexual; perianth white, pink, or yellow. |
| ............ ............ ............ ............ ............ ........35 Stems of fertile and sterile individuals simple (never branched); inflorescence a terminal raceme or panicle (Maianthemum) or axillary racemes or clusters of 1-9 flowers (Polygonatum); fruit a berry. |
| ............ ............ ............ ............ ............ ..........36 Inflorescence terminal, a raceme or panicle; tepals separate; leaves with 3 main parallel veins, acute to acuminate at the apex; foliage green, not glaucous |
| ............ ............ ............ ............ ............ ..........36 Inflorescence of 1-several axillary flowers; tepals fused; leaves with > 7 main parallel veins, obtuse to acute at the apex; foliage blue-green, glaucous |
| ............ ............ ............ ............ ............ ........35 Stems of fertile individuals branched (always at least bifurcate), but sterile individuals in some genera characteristically unbranched; inflorescence either of 1 (-2) flower(s) borne in a leaf axil (Uvularia, Streptopus), or of (1) 2 (-3) flowers borne terminally opposite the last leaf (Prosartes); fruit a berry or capsule. |
| ............ ............ ............ ............ ............ ............ 37 Leaves perfoliate; fruit a capsule |
| ............ ............ ............ ............ ............ ............ 37 Leaves sessile (though sometimes slightly to strongly clasping); fruit a berry or capsule. |
| ............ ............ ............ ............ ............ ............ ..38 Stem brown, wiry, puberulent; last 2 leaves (near stem tip) on each branch approximate to one another (sometimes subopposite) and with noticeably oblique bases; flowers and fruits terminal on the branches |
| ............ ............ ............ ............ ............ ............ ..38 Stem green, not wiry, glabrous; last 2 leaves (near stem tip) on each branch no closer together than other leaves, with symmetrical bases; flowers (and fruits) either terminal on the branches or solitary and axillary to most leaves. |
| ............ ............ ............ ............ ............ ............ ....39 Flowers and fruits in single terminal clusters (sometimes appearing axillary, but still only one cluster per branch of the stem); tepals pale to rich yellow |
| ............ ............ ............ ............ ............ ............ ....39 Flowers and fruits 1 (-2) in the axils of many leaves; tepals white to pink |