1 Leaves simple; plant a tree or shrub.

  2 Leaves either cordate and < 2× as long as wide, or linear and > 10× as long as wide; leaves opposite, alternate, or 3-whorled (or a mixture of those arrangements); [collectively widespread in our area]; fruit a capsule (dehiscent), narrowly cylindrical, (9-) 14-30 (-36) cm long, < 1.5 cm in diameter; [tribe Catalpeae].

    3 Leaves linear (> 10× as long as wide, with a narrowly cuneate base; stamens 4; shrub to small tree; [TX westwards and southwestwards]

  2 Leaves spatulate to obovate, 2-6× as long as wide; leaves alternate (though sometimes closely fascicled on short (spur) shoots, with the arrangement difficult to discern); fruit a berry (indehiscent), spherical, elliptical, or obovoid, 5-35 cm long, 4-35 cm in diameter; [s. peninsular FL only in our region]; [tribe Crescentieae].

      4 Leaves obovate, mostly widest ½ to ¾ of the way from blade base to apex; leaves alternate and spaced along main branches; berry 5-12 cm long, elliptical or obovoid, the apex extended as a blunt point

      4 Leaves spatulate, mostly widest at a point > ¾ of the way from blade base to apex; leaves alternate but closely fascicled on short (spur) shoots, with the arrangement difficult to discern; berry 15-35 long, spherical, the apex smoothly rounded

1 Leaves compound; plant a liana, tree, or shrub.

        5 Leaves either all 2-foliolate, with a tendril in the terminal position (this often withered and absent on older leaves), or a mixture of 2-foliolate and 3-foliolate, with at least some leaves on a branch 2-foliolate; plant a liana; [tribe Bignonieae].

          6 Leaflets <1.5× as long as wide, the venation subpalmate (usually with 5 veins palmate or nearly so at the blade base); leaf bases cordate to subcordate; leaf apices abruptly acuminate; corollas white or cream, with a yellow throat; fruit ellipsoid, 1.5-2.5× as long as wide, the surface strongly echinate; tendrils terminating in expanded adhesive disks

          6 Leaflets 1.3-5× as long as wide, the venation pinnate; leaf bases cordate, subcordate, auriculate, truncate, rounded, or cuneate; leaf apices abruptly to gradually acuminate; corollas red, orange, bright yellow, or pink; fruit linear or ellipsoid, > 6× as long as wide, the surface smooth; tendrils narrowing to pointed tips.

             7 Tendrils hooked, claw-like, the 3 equal branches each with a stiff, sharply-pointed hook-like tip; corollas bright yellow on inside and outside

             7 Tendrils not hooked, not claw-like, the 3 or more branches usually unequal and flexuous when fresh (though sometimes curved at the tip).

               8 Corollas pink, the tube white or paler pink; tendrils simple; fresh foliage with garlic odor when bruised; [exotic, FL peninsula]

               8 Corollas red to orange-red, sometimes with yellow as well; tendrils with 3 or more branches; fresh foliage not garlic-scented; [collectively widespread].

                 9 Corollas red to red-orange, the corolla lobes often with a yellow inner surface; lower 3 corolla lobes each 1-1.5× as long as wide, the lateral 2 descending; pseudostipules leaflike, at petiole base, ovate or orbicular; corolla tube 1.5-3× as long as the diameter; [widespread native in our region, south to c. peninsular FL, and also cultivated]

                 9 Corollas uniformly red to red-orange; lower 3 corolla lobes 2-4× as long as wide, the lateral 2 born at 90 degrees to the lower and therefore at 180 degrees to one another; pseudostipules absent or minute; corolla tube 5-9× as long as the diameter; [exotic, FL peninsula]

        5 Leaves 3-many-foliolate; plant a tree, shrub, or liana.

                   10 Leaves palmately compound, with (3-) 5 (-7) leaflets; [exotic, FL peninsula]; [tribe Crescentieae].

                     11 Leaves, young branches and inflorescence with indumentum of simple, branched or stellate hairs; corollas yellow

                     11 Leaves, young branches and inflorescence with indumentum of stalked or sessile lepidote scales; corollas yellow or pink

                   10 Leaves pinnately or bipinnately compound, with (5-) 7-many leaflets; [collectively widespread in our region].

                       12 Leaves bipinnately compound; trees; [FL peninsula].

                          13 Leaflets 0.3-1.2 cm long; corollas lavender-blue; [tribe Jacarandeae]

                          13 Leaflets 4-7 cm long; corollas white to pale yellow; [tribe Tecomeae]

                       12 Leaves pinnately compound; shrubs, lianas, or trees; collectively widespread in our region].

                            14 Leaflet margins entire; plant a tree; corolla campanulate; calyx splitting along the lower side, appearing spathe-like; [s. FL only]; [tribe Coleae]

                            14 Leaflet margins serrate; plant a liana, shrub, or small tree; corolla tubular or funnel-like; calyx not splitting; [collectively widespread in our area, including FL peninsula]; [tribe Tecomeae].

                              15 Plant a liana; [collectively widespread in our region].

                                16 Corollas yellow or yellowish-orange; calyx green to orange-red colored; plants climbing by adventitious roots from the stems; [native, widespread in our region]

                                16 Corollas pink, with purplish lines in the throat; calyx white to pink; plants not climbing by adventitious roots; [exotic, FL peninsula]

                              15 Plant a shrub or small tree; [FL peninsula only; exotic].

                                  17 Corolla yellow; corolla tube straight; leaflet margins finely serrate; leaflet apex acute

                                  17 Corolla orange; corolla tube narrow, strongly curved-arching; leaflet margins coarsely serrate; leaflet apex rounded to sub-acute

1 Leaves tiny, bract-like, triangular, 6-14 (-17) per node

1 Leaves either needle-like, scale-like, or flattened and large, (2-) 3-4 (-6) per node.

  2 Leaves needle-like or scale-like, terete, angled, or flat in ×-section, < 2 cm long; leaves (2-) 3-4 (-6) per node

  2 Leaves flat, > 3 cm long; leaves (2-) 3 per node; [Eudicots].

    3 Plant a subshrub, < 3 dm tall, with < 10 leaves per stem.

      4 Leaves entire, broadly elliptic; flowers numerous, in a hemispherical head, subtended by 4 large white bracts

      4 Leaves serrate, narrowly ovate or narrowly obovate; flowers (1-) 2-8 in a long-peduncled umbel or corymb, not subtended by bracts

    3 Plant a shrub or tree, > 3 dm tall, with many > 10 leaves per stem.

        5 Leaves toothed, and most leaves also lobed

        5 Leaves entire, not lobed.

          6 Leaves cordate at base, about as long as wide; medium to large tree.

             7 Flowers lavender; capsules ellipsoid, < 2× as long as wide; leaf undersurface with branched (dendritic or stellate) hairs; nectar glands absent

          6 Leaves cuneate to rounded at base; leaves > 1.5× as long as wide; shrub to small tree.

               8 Leaves rounded or retuse at the tip (at least some obviously rounded in Pittosporum).

                 9 Fruit a large, globose berry (2-8 cm in diameter), pale brown in color when mature, the surface roughened in texture; petioles with a decurrent, adaxial wing forming a groove; sepals rusty tomentose

                 9 Fruit a capsule, dehiscing alonge 1 or 5 sutures; petioles lacking a decurrent, adaxial wing forming a groove; sepals variously glabrous to pubescent, but not rusty tomentose.

                   10 Ovaries 5-10-carpellate; capsules dehiscing along 5 sutures.

                   10 Ovaries 2-carpellate; capsules dehiscing along one major adaxial suture, appearing berry-like before dehiscence, the seeds often surrounded by a glutinous material

               8 Leaves acute to acuminate at the tip.

                     11 Leaves lanceolate or oblong-elliptic to narrowly ovate (> 2.5× as long as wide), the secondary venation not prominent nor arching-parallel (except Decodon); inflorescences axillary or terminal; flowers pink or white.

                       12 Inflorescences axillary; flowers pink; leaves thin and herbaceous, with prominent secondary veins arching parallel with the margin, also with branching hairs on the abaxial leaf midvein; plants with arching stems, these often tip-rooting; [native plants of wetlands]

                       12 Inflorescences terminal or axillary; flowers pink or white; leaves thick and leathery, lacking prominent secondary veins; plants not tip-rooting nor with branching hairs on the midvein; [exotics of uplands or wetlands, persistent or weakly naturalized]

                          13 Fruit berry-like with 2-locular ovaries; flowers white-colored, smaller; inflorescence axillary or pseudo-terminal.

                          13 Fruit follicles; flowers variously colored (including white), showy and salverform; inflorescence terminal.

                            14 Plants trees, 2-60 m tall, with a single or multiple stem(s); latex milky; flowers white or cream colored, the anthers not connivent and not adhering to stigmas; [uncommon non-natives, s. FL]

                            14 Plants shrubs, 10-40 dm tall, much branched from the base; latex clear; flowers white, pink, or red, the anthers connivent and adhering to the stigmas; [commonly cultivated in our area (and sometimes persistent), particularly near the coast; NC s. to FL, w. to TX]

                     11 Leaves ovate (< 2× as long as wide), the secondary venation prominent and arching-parallel; inflorescences terminal; flowers white, greenish-yellow, red, or orange.

                              15 Flowers in a spherical or hemispherical head; corollas white or greenish-yellow; fruit a globose cluster of nutlets (dry)

                              15 Flowers in a monochasial helicoid cyme; corollas red to orange; fruit a red to black berry (fleshy)

1 Leaves pinnately lobed.

  2 Leaves harshly scabrous on the upper surface; leaves typically a mix of alternate, opposite, and whorled

  2 Leaves glabrous or glabrescent on the upper surface; leaves strictly opposite

1 Leaves palmately lobed.

    3 Plants climbing by twining; stems with retrorse prickles; foliage scabrous

    3 Plants erect trees or shrubs; stems not prickly; foliage smooth or pubescent, but not scabrous.

      4 Leaves 3-9-lobed, the margins generally serrate or sublobed; fruit either a drupe or a schizocarp of 2 samaroid mericarps (maple “keys”).

        5 Fruit a schizocarp of 2 samaroid mericarps (maple “keys”); stamens (4-) 8 (-12); small to large trees; petioles >1× as long as the leaf blade

        5 Fruit a drupe; stamens 5; shrubs; petioles < ¾× as long as the leaf blade

      4 Leaves 3-lobed, the margins entire; fruit a capsule.

          6 Flowers lavender; pods ellipsoid, < 2× as long as wide; leaf undersurface with branched (dendritic) stellate hairs; nectar glands absent

1 Leaves deciduous (medium to pale green, thin in texture); leaves strictly opposite.

  2 Leaves 10-70 cm wide, cordate or subcordate at the base; flowers 5-merous, bilaterally symmetrical, large (20-70 mm long), the petals connate into a tube; fruit a capsule.

    3 Flowers lavender; capsules ellipsoid, < 2× as long as wide; leaf undersurface with branched (dendritic or stellate) hairs; nectar glands absent

  2 Leaves 1-12 cm wide, cuneate to rounded at the base; flowers 4-6-merous, radially symmetrical, small to medium (< 25 mm long), the petals either connate into a tube or separate and clawed; fruit a drupe or capsule.

      4 Leaves with prominently parallel-arcing secondary veins; corolla 4-merous, < 8 mm long, white to cream; inflorescence a many-flowered corymb or head; flowers white to cream; fruit a drupe

      4 Leaves with complexly branching secondary and tertiary veins; corolla 5-6-merous, 12-25 mm long, either greenish-yellow and mottled with purple, or white, pink, or purple; inflorescence a few-flowered cyme or many-flowered cymose panicle; fruit a capsule.

        5 Leaves 4-20 cm long, 2.5-12 cm wide; petals connate into a 15-25 mm long tube, either greenish-yellow and mottled with purple; some calyx lobes expanding to 7 cm long and 5 cm wide, petaloid (pink to yellowish); capsule 2-valved; [native, in saturated, boggy seepages and streamheads, se. SC to FL]

        5 Leaves 2.5-7 cm long, 1.5-4 cm wide; petals separate, clawed, 12-20 mm long (including the 6-9 mm long claw), white, pink, or purple; calyx remaining small and sepaloid (3.5-5 mm long); capsule 4-6-valved; [introduced, persistent from planting in upland to moist situations]

1 Leaves evergreen (dark green or gray-green, thick in texture); leaves opposite or subopposite (offset by < 2mm from the opposing leaf).

          6 Mangroves, with one of various adaptations to growing in tidal or near-tidal, saline situations: prominent salt-excreting glands on the petiole (Laguncularia in COMBRETACEAE), or prop roots (Rhizophora in RHIZOPHORACEAE), or abundant pneumatophores (Avicennia in ACANTHACEAE); [FL and less commonly subtropical shores of other, especially Gulf Coast, southeastern states].

             7 Leaves broadly elliptic, light green on both surfaces, rounded to broadly cuneate at the base, rounded and often retuse at the tip; petiole with 2 prominent salt-excreting glands; plants with neither prop-roots from the trunk and branches, nor pneumatophores from the roots

             7 Leaves narrowly elliptic, dark green above, cuneate at the base, acute to obtuse at the tip; petiole without salt glands; plants with either prop-roots from the trunk and branches, or pneumatophores from the roots.

               8 Plants with numerous pneumatophores ascending from the roots and terminating in a blunt tip; leaves gray on the undersurface

               8 Plants with prominent prop-roots descending to the ground from the trunk and branches; leaves light green on the undersurface

          6 Non-mangroves; [collectively widespread].

                 9 Secondary leaf veins relatively few (or diffuse), further branching and reticulating into the tertiary vein structure (or in Santalum and Strychnos the veins brochidodromous, arching away from and not completely reaching the margins of the blades); [collectively widespread].

                   10 Petioles prominently 2-ribbed; fruits drupeaceous, bearing an apical rimmed collar; [plants trees or shrubs, sometimes scrambling; uncommon non-native in s. FL]

                   10 Petioles not (or only scarsely) 2-ribbed; fruit a capsule, berry, or drupe (if a drupe, then not apically rimmed, as in OLEACEAE); [plants upright, natives and non-natives, collectively widespread].

                     11 Leaves strictly opposite, blue- or gray-green on both surfaces, suborbicular (about as wide as long), strongly aromatic when fresh

                     11 Leaves opposite or subopposite (offset by < 2mm from the opposing leaf); dark green above, pale green below; oblancolate, elliptic, or ovate (distinctly longer than wide), not aromatic when fresh

                       12 Twigs with spines; leaf venation with 3 primary veins from near the blade base; fruit a spherical berry, 5-12 cm long

                       12 Twigs lacking spines; leaf venation pinnate; fruit an elliptical drupe, < 2.5 cm long

                 9 Secondary leaf veins many and conspicuous, closely parallel to one another and extending unbranched to the leaf margin.

                          13 Leaves elliptic, widest near the midpoint of the blade, ca. 2× as long as wide; flowers in axillary thyrses; fruit a 1-seeded drupe, 2-4 cm long

                          13 Leaves spatulate, widest towards the broadly rounded tip, ca. 1.2-1.6× as long as wide; flowers terminal on the branches, 1-3; fruit a leathery capsule, (4-) 6-9 (-12)-valved, 5-8 cm long