1 Leaves opposite (to subopposite).

  2 Branches armed, secondary branches (short shoots) thorn-tipped; Leaf margins serrulate, serrate, or crenate; leaf apex acuminate or acute; drupe with 2-4 stones; petals 4 or 5, white, cream, or yellow; [collectively widespread in our region].

    3 Leaves (2-) 4-10 (-13) cm long; inflorescence a fascicle or flower solitary; sepals 4; petals 4; flowers functionally unisexual (the stamens rudimentary in the pistillate flowers); [exotics, mainly inland and/or northwards in our area]

    3 Leaves 1.5-4 (-6) cm long; inflorescences a panicle-like thyrse; sepals 5; petals 5; flowers bisexual; [native, of the Coastal Plain]

  2 Branches unarmed; leaf margins entire; leaf apex either slightly to deeply notched or acute to acuminate; drupe with 1 stone; petals 5 or absent; [FL peninsula or TX].

      4 Leaf blades gland-dotted on the undersurface; petals 5; [TX]

      4 Leaf blades not gland-dotted; petals 0; [FL peninsula].

        5 Drupes 5-8 (-12) mm long; secondary veins borne mostly at a 50-75° angle to the midvein, and arching as they approach the margin; sepals crested on the upper surface

        5 Drupes 10-20 mm long; secondary veins borne mostly at a 70-90° angle to the midvein, and remaining straight before splitting Y-fashion as they approach the margin; sepals with a slight keel on the upper surface

1 Leaves alternate.

          6 Plant a woody vine.

             7 Leaf margins entire; leaf apex obtuse (to short-acuminate); tendrils absent (plant climbing by twining); [widespread in our area]

          6 Plant a shrub (sometimes clambering) or small tree.

               8 Leaves with 3 (-5) prominent veins from near the base (and 1-3 additional pairs of veins along the midvein); leaf margins toothed (serrate or crenate).

                 9 Leaves 7-17 cm long; inflorescence repeatedly branched dichotomously; peduncles fleshy and reddish in fruit; nectariferous disc pubescent.

                 9 Leaves 0.2-10 cm long; inflorescence a fascicle, cyme, thyrse, umbel-like, or panicle-like; peduncles neither fleshy nor red; nectariferous disc glabrous.

                   10 Plants armed with stipular spines; fruit either fleshy (a drupe with 1 stone), or dry (a 1-seeded samara).

                     11 Fruit dry (a 1-seeded samara)

                     11 Fruit fleshy (a drupe with 1 stone)

                   10 Plants not spiny; fruit dry, a 3-locular capsular with many seeds; [tribal placement uncertain].

                       12 Erect shrubs to 1.5 m tall; inflorescence panicle-like or umbel-like, with many flowers (> 20)

                       12 Clambering shrub to 8 m tall; inflorescence 1 2-7-flowered thyrse or the flower solitary

               8 Leaves either with prominently pinnate venation (the lowermost lateral veins no more prominent than others) or with no prominent lateral veins; leaf margins either entire or toothed (serrate or crenate).

                          13 Fruits dry, a 3-locular capsule with many seeds; ovary ½-inferior; branches unarmed

                          13 Fruits fleshy, a drupe with 1-4 stones; ovary superior; branches either unarmed, or armed with thorn-tipped secondary short shoots and sometimes also with stipular spines.

                            14 Drupe with 1 stone; leaves 0.5-3 cm long, entire, 1-veined, the apex notched; branches armed with thorn-tipped secondary short shoots and sometimes also with stipular spines; [TX, peninsular FL]

                              15 Leaves pinnately veined; drupes 3-6 mm in diameter; style 1; petals 0; [TX]

                              15 Leaves with no venation apparent other than the midvein; drupes 5-10 mm in diameter; leaves with no venation apparent other than the midvein; style 2-4; petals 5; [TX or peninsular FL]

                                16 Drupe yellow or orange (drying brownish); inflorescence a fascicle; petals white

                                16 Drupe blue to purple, 5-10 mm long; inflorescence a thyrse on a short (1-2 mm) peduncle; petals yellow

                            14 Drupe with 2-4 stones; leaves (2-) 4-13 cm long, toothed (serrate or crenate), with prominently pinnate venation, the apex acuminate, acute, or obtuse; branches unarmed; [collectively widespread].

                                  17 Winter buds naked, pubescent; flowers perfect, sepals, stamens, and petals 5; style undivided; leaves with 8-10 lateral veins on either side of the midvein

                                  17 Winter buds with bud scales; flowers functionally unisexual, sepals and stamens 4 or 5 (the stamens rudimentary in the pistillate flowers), petals 0 or 4 (never 5); style divided for 1/3 to 2/3 its length into 2, 4 or 5 segments; leaves with (2-) 3-9 lateral veins on either side of the midvein

1 Leaves serrate.

  2 Leaf venation palmate, the leaf often lobed or at least pentagonal in shape (as well as serrate); plants climbing by leaf-opposed tendrils

  2 Leaf venation pinnate, the leaf neither lobed nor pentagonal; plants climbing by other mechanisms (see below).

    3 Plants climbing by adventitious roots, by twining, or by growing through bark layers of Taxodium ascendens or Chamaecyparis thyoides; [collectively widespread in our region].

      4 Plants climbing by adventitious roots; leaf base cordate or subcordate, and also slightly to strongly oblique

      4 Plants climbing by twining, or by growing through bark layers of Taxodium ascendens or Chamaecyparis thyoides; leaf base cuneate, rounded, or cordate.

        5 Leaves strongly cordate at the base, 7-15 cm wide

        5 Leaves cuneate, rounded, or subcordate at the base, 0.3-8 cm wide.

          6 Leaf blades mostly 2-6 cm long, 0.3-2 cm wide; plants climbing by growing through bark layers of Taxodium ascendens or Chamaecyparis thyoides

          6 Leaf blades mostly 6-13 cm long, 3-8 cm wide; plants climbing by twining

1 Leaves entire.

             7 Stems with well-developed prickles; tendrils paired, stipular (diverging from the leaf petiole above its base); [Monocots]

             7 Stems lacking prickles; tendrils either absent or (if present) not stipular and paired; [Eudicots or Basal Angiosperms].

               8 Plant climbing by dense, reddish adventitious roots

               8 Plant climbing by twining or by tendrils.

                 9 Plant climbing by tendrils

                 9 Plant climbing by twining.

                   10 Leaves elliptic or ovate, obviously longer than broad, most leaves > 1.4× as long as wide; leaf blade base narrowly cuneate, broadly cuneate, rounded, or subcordate.

                     11 Leaves 3-8 cm long, rounded to broadly cuneate at the base and rounded or obtuse at the apex; lateral leaf veins straight, parallel, not forking; inflorescence a terminal thyrse or panicle

                     11 Leaves 6-15 cm long, cuneate at the base and acuminate at the apex; lateral leaf veins forking at or beyond the middle; inflorescence a solitary, axillary flower

                   10 Leaves orbicular to very widely ovate, most leaves < 1.4× as long as wide; leaf blade base deeply cordate, subcordate, rounded, or broadly cuneate

                       12 Leaf venation pinnate, but “pseudopalmate”, with 3 primary veins from the marginal point of attachment of the petiole, the 2 lateral veins then promptly rebranching (< 1 cm from the leaf base) into 2-3 prominent veins (the remainder of the venation pinnate along the midvein); basalmost pair of primary veins exposed (lacking leaf tissue) on their basal side for > 2 mm; leaf blade base deeply cordate; leaf with no tendency to lobing, the leaf outline convex from the base to the apex (except in the immediate vicinity of the petiole and sometimes immediately near a slightly acuminate apex

                       12 Leaf venation palmate, with (3-) 5-9 primary veins from the marginal or peltate point of attachment of the petiole, these primary veins then rebranching well above the leaf base; basalmost pair of primary veins completely included within leaf tissue; leaf blade base cordate, subcordate, rounded, or broadly cuneate; leaf with a tendency to lobing, the leaf outline with 1 or more concave areas between the base and the apex (except Cissampelos of s. FL)