1 Plant a woody vine; leaves simple; [subfamily Aralioideae; tribe Schefflereae]

1 Plant an herb, shrub, or tree (if a partially scandent shrub, then the stems also with conspicuous recurved prickles as in Eleutherococcus trifoliatus); leaves simple or compound.

  2 Leaves simple, peltate or cordate, roundish (if lobed, with 3-5 rounded lobes), 0.3-10 cm wide; rhizomatous, creeping herbs; [subfamily Hydrocotyloideae]

  2 Leaves either compound OR simple and palmately lobed and > 10 cm wide (the lobes 5-15 per leaf); herbs, shrubs, or trees.

    3 Leaves simple, palmately-lobed; [subfamily Aralioideae; tribe Schefflereae].

      4 Leaves 5-7-lobed (the lobes not themselves sublobed); tree, the branches armed with prickles

      4 Leaves 7-15-lobed (the lobes themselves either sublobed or not); robust herb to shrub, the branches unarmed.

        5 Leaves 7-9-lobed (the lobes not sublobed); ovary 5- or 10-carpellate; leaf blades glabrous beneath at maturity

    3 Leaves compound.

          6 Leaves 2-3× compound, at least the final order of division pinnate; leaves either 1 from a subterranean stem or 2-many, alternate on an aboveground stem; inflorescence compound, consisting of (2-) 3-many umbels, either on a separate peduncle from the rhizome or in a terminal panicle or raceme of umbels; fruit purple or black; [subfamily Aralioideae; tribe Aralieae]

          6 Leaves 1× palmately compound, leaflets 3-7; leaves 3-5 in a whorl at the summit of the stem (Panax) or many, clustered on spur shoots (Eleutherococcus); inflorescence of a single, simple umbel borne terminally on the stem; fruit red to yellow (Panax), purple or black (Eleutherococcus) or orange (Heptapleurum).

             7 Plant non-native shrubs or trees (sometimes partially epiphytic or scandent); with or without stem prickles; fruit black, dark purple, or orange; [subfamily Aralioideae; tribe Schefflereae].

               8 Plant a shrub (to 7 m tall), with prominent stem prickles; fruit black or dark purple when ripened; leaves either trifoliate (E. trifoliatus) or palmately compound and 5-foliolate (predominantly so in E. sieboldianus)

               8 Plant a shrub (to 4 m tall in H. arboricola) or tree (to 12 m tall in H. actinophyllum), lacking stem prickles; fruit orange when ripened; leaves palmately compound, usually 7-9-foliolate (occasionally with 5 or 10 leaflets, if 5, this not predominant across the plant)

             7 Plant native herbs, lacking prickles; fruit red or yellowish-green; [subfamily Aralioideae; tribe Aralieae].

                 9 Leaflets 3 (-5), sessile or subsessile, the petiolules 0-3 mm long; larger leaflets 4-8 cm long, 0.5-2.5 cm wide, averaging about 2.5× as long as wide, the apex obtuse to acute; fruit yellow-green when ripe, longitudinally winged and ribbed in ×-section; petals white (rarely tinged with pink); inflorescence nodding in bud; underground storage organ a spherical tuber

                 9 Leaflets (3-) 5, petiolulate, the petiolules (7-) 10-25 mm long; larger leaflets 6-15 cm long, 3.5-7 cm wide, averaging about 1.8× as long as wide, the apex acuminate; fruit bright red when ripe, smoothly elliptical in ×-section; petals light green; inflorescence erect in bud; underground storage organ an elongate root, this vertical or horizontal, and sometimes branched

1 Lianas.

  2 Lianas climbing by adventitious roots

  2 Lianas climbing by twining or by tendrils.

    3 Lianas climbing by twining

    3 Lianas climbing by tendrils.

      4 Tendrils branched, leaf-opposed; leaves mostly 5-7-lobed, the margins also serrate or dentate

      4 Tendrils simple (though paired in Smilax in SMILACACEAE), axillary; leaves 3-lobed, the margins entire, serrulate, or prickly.

        5 Leaves longer than wide, entire or prickly-margined; stems usually obviously armed with prickles; flowers 6-merous, greenish, in umbels borne in leaf axils; tendrils stipular, 2 per leaf axil, adnate to the petiole basally

        5 Leaves wider than long, entire or serrulate; stems not armed; flowers 5-merous, blue-purple or yellow, solitary or in small fascicles in leaf axils; tendrils 1 per leaf axil

1 Trees or shrubs.

          6 Trees.

             7 Leaves > 3 dm long and wide; tree monopodial, with a single, unbranched stem (rarely with a few branches).

               8 Leaf lobes > 15, not sublobed; venation of each lobe parallel; fruit a drupe, with 1 seed; [Monocots]

               8 Leaf lobes < 13, most of these sublobed; venation of each lobe pinnate; fruit either a many-seeded berry or a single-seeded nutlet; [Eudicots].

                 9 Petiole attachment marginal; leaf lobes mostly sublobed; fruit a large berry, with many seeds

                 9 Petiole attachment peltate; leaf lobes not sublobed; fruit an nutlet, single-seeded

             7 Leaves < 3 dm long and wide; tree branching; [Eudicots].

                   10 Leaves 2-lobed (deeply notched at the apex), each lobe separated by the midvein, asymmetrical; [peninsular FL and s. TX]

                   10 Leaves 3-5 (-7) lobed; [collectively widespread].

                     11 Leaf blades (3-) 5 (-7) lobed, to 15 cm wide and long, each lobe finely serrate-crenate (>3 teeth per cm of margin) and rarely with a small sub-lobe; multiple fruit spherical and spiky, consisting of multiple bird-beak-like loculicidal capsules; buds axillary

                     11 Leaves 3 (-5)-lobed, to 35 cm wide and long, each lobe coarsely toothed or sublobed, the teeth or sublobes (at most 1-2 per cm of margin) attenuate-acuminate; multiple fruit spherical and merely rough on the surface, consisting of multiple achenes with tawny bristles; buds infrapetiolar (completely hidden in the swollen petiole base)

          6 Shrubs.

                       12 Leaf lobe margins entire (or undulate to sublobed at the tip).

                          13 Leaves bilobed; fruit a legume

                          13 Leaves palmate, usually with at least 3-7 lobes; fruit a capsule

                       12 Leaf lobe margins serrate.

                            14 Leaves glabrous

                            14 Leaves pubescent (slightly or strongly).

                              15 Pubescence of simple hairs; plants armed or not with nodal spines

                                16 Leaves 10-30 cm long and wide; fruit a berry; inflorescence of solitary to a few flowers, or a raceme

                                16 Leaves 2-10 cm long and wide; fruit an aggregate of drupelets; inflorescence a cyme

                              15 Pubescence of stellate hairs; plants unarmed.

                                  17 Leaves < 15 cm wide