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| 1 Leaves 2-3-foliolate. |
| ..2 Leaves 2-foliolate, with a branched tendril in the terminal position (this sometimes not developed, or withered); liana |
| ..2 Leaves 3-foliolate, lacking tendrils; shrub, liana, or tree. |
| ....3 Upright shrub or tree. |
| ......4 Leaflets entire, glandular-dotted; [n. FL southwards |
| ......4 Leaflets serrate or serrulate, not glandular-dotted; [collectively widespread]. |
| ........5 Leaflets 3-5 (-7), coarsely and jaggedly serrate, with < 5 teeth per leaflet side; fruit a schizocarp of 2 samaroid mericarps (maple “keys”) |
........5 Leaflets 3, evenly serrulate, with > 10 teeth per leaflet side; fruit an inflated capsule |
| ....3 Liana or sprawling shrub. |
| ..........6 Flowers yellow with fused petals; stems stiff, green |
| ..........6 Flowers either white, radially symmetrical, with separate petaloid sepals (Clematis), or blue, bilaterally symmetrical, with fused petals (Vitex). |
| ............ 7 Leaves 3-more-foliolate; flowers white, radially symmetrical, uniseriate, with white petaloid sepals and no petals |
| ............ 7 Leaves 1 (-3) foliolate; flowers blue, bilaterally symmetrical, biseriate, with green calyx and blue corolla |
| 1 Leaves 4-15-foliolate. |
| ............ ..8 Leaves palmately compound. |
| ............ ....9 Leaflets serrate; flowers white, yellow, or red; fruit a leathery capsule, irregularly spheroidal, 2-9 cm in diameter, with 1-3 (-6) large seeds, each with a large pale hilum contrasting with the dark brown color of the rest of the seed |
| ............ ....9 Leaflets entire; flowers blue, pink, or purple; fruit either a 4-seeded drupe, < 0.5 cm in diameter, or an elongated capsule, 8-10 cm long and ca. 0.7 cm in diameter. |
| ............ ......10 Leaflets < 3× as long as wide, broadly rounded at the tip; fruit an elongated capsule, 8-10 cm long and ca. 0.7 cm in diameter [peninsular FL] |
| ............ ......10 Leaflets > 4× as long as wide, acute at the tip; fruit a 4-seeded drupe, < 0.5 cm in diameter; [widespread in our region] |
| ............ ..8 Leaves pinnately compound, bipinnately compound, or more complexly compound. |
| ............ ........11 Plant a liana (woody vine). |
| ............ ..........12 Leaves pinnately compound, with 7-15 coarsely serrate leaflets; perianth biseriate, with a green synsepalous calyx and an orange sympetalous corolla; fruit an elongate capsule, with many winged seeds; stems to 20 cm in diameter, with tan bark |
| ............ ..........12 Leaves either pinnately compound, the leaflets 3-7 and coarsely serrate, or more complexly compound, the leaflets 5-many, not serrate though often lobed; perianth uniseriate, with a white, pink, or purplish aposepalous calyx and no corolla; fruit an aggregate of plumose achenes; stems to 1 cm in diameter, brown or green |
| ............ ........11 Plant a tree or shrub, with stiff branches. |
| ............ ............ 13 Leaves 3-7-foliolate and strictly 1-pinnate; leaflets with a few very coarse teeth; 1st year stems green; fruit a pair of winged, asymmetrical samaroid mericarps |
| ............ ............ 13 Leaves 3-15-foliolate, 1-pinnate or partially 2-pinnate; leaflets evenly serrate with many teeth or entire; 1st year stems tan to brown (very new growth may be green); fruit either a symmetrical (winged) samara (Fraxinus) or a purplish-black, many-seeded berry (Sambucus). |
| ............ ............ ..14 Fruit a purplish-black or red, 4-seeded berry (Sambucus); plant a shrub or small tree; stems hollow or pithy; petiole prominently grooved on the upper side; fresh leaves somewhat fleshy in texture |
| ............ ............ ..14 Fruit either a green or tan, symmetrical (winged) samara or a blackish 5-seeded dryish drupe; plant a small to large tree; stems solid and woody; petiole nearly round in ×-section (not grooved); fresh leaves membranaceous or coriaceous in texture. |
| ............ ............ ....15 Fruit a symmetrical samara; axillary buds suprapetiolar (though sometimes almost hidden within the strongly U-shaped petiolar attachment; [common native (also planted)] |
| ............ ............ ....15 Fruit a nearly spherical 5-seeded dry drupe; axillary buds infrapetiolar (hidden by the swollen petiole base; [rarely escaped alien] |