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1 Fruits 12-30 mm long, yellow, orange, or brown at maturity; petals unlobed (or with vestigial lateral lobes); petioles 14-51 mm long; leaf margins usually slightly to very obviously undulate; [peninsular FL (from Volusia and Manatee counties southwards)]
..2 Branches undifferentiated into short shoots and long shoots; branches unarmed; ovary glabrous; large trees to 25 m tall (though often smaller); [tropical s. FL (from Martin and Collier counties southwards)].
..2 Branches differentiated into short shoots (bearing most leaves, with very short internodes) along long shoots; branches armed with thorns; ovary pubescent at anthesis (becoming glabrous in fruit); small trees or shrubs, less typically medium trees to 20 m tall; [collectively widespread in our region, including tropical s. FL].
....3 Leaves, twigs, pedicels, and sepals glabrous even when young (or with a very few and inconspicuous white strigose hairs); leaf blades not conspicuously reticulate on the lower surface; styles 2.2-2.8 mm long; [se. and s. TX southwards, FL peninsula (Brevard and Levy counties southwards)].
....3 Leaves, twigs, pedicels, and sepals with densely to sparsely hairy surfaces (at least when young); leaf blades conspicuously reticulate on the lower surface (the secondary, tertiary, and finer veins impressed or flush to the lower leaf surface when fresh, slightly to strongly raised when dry (the reticulum is hard to observe in species with dense and persistent vestiture); styles 0.9-1.8 mm long; [section Frigoricola].
........5 Petioles densely shaggy-strigose, the hairs white to gray; [dry habitats, c. OK, c. TX, s. TX westwards and southwards]
..........6 Berries (7-) 9-16 mm long; central corolla lobe 1.8-2.0 mm long; leaf trichomes transparent and colorless, often flattened in ×-section (use at least 20× magnification); stomatal chamber openings closed to a narrow slit, the guard cells not visible through the opening; [widespread in our region]
..........6 Berries 4-9 mm long; central corolla lobe 1.1-1.3 mm long; leaf trichomes opaque, light brown to gray, mostly terete in ×-section; stomatal chamber openings wide and elliptic, the guard cells visible through the opening; [moist to wet habitats, SC, GA, and FL west to sw. LA]
............ ..8 Young twigs glabrous or with a few scattered, quickly deciduous pale trichomes; twig surface green to cream-white, becoming light grey; leaf pubescence silvery-white to very slightly golden
............ ....9 Mean pedicel length (2-) mean 4.8 (-11) mm long; largest leaves on short shoots almost all < 4.5 cm long; leaf undersurface typically tawny to very dark brown, and appears dull and finely woolly, rarely silky-sericeous; plants usually clonal shrubs; [c. FL ridges]
............ ....9 Mean pedicel length (4-) mean 9.3 (-15) mm long; largest leaves on short shoots to 8 cm long (usually some at least on a plant > 5 cm long); leaf undersurface tawny to light golden to even silvery-white, most often appearing silky and lustrous, when dull and woolly, with most trichomes straight, appressed, multi-layered, and co-oriented, completely obscuring the leaf surface, but with a large proportion of trichomes that are curled and ascending, dulling the luster; plants usually many-stemmed, clumped shrubs to single-trunked trees; [e. NC south to s. FL, mainly in maritime situations]
............ ........11 Pubescence on young twigs moderate to dense, blonde to light brown, rarely persisting past the first season; abaxial leaf pubescence blonde to light brown, sparse; staminodes only to 1/3 to 1/2 the length of the median corolla lobes; ovary glabrous or with a few trichomes medially; seed uniformly brown; stomatal chamber openings atop ellipsoidal domes neatly bordered by one or more concentric cuticular ridges
............ ........11 Pubescence on young twigs dense, rusty dark red-brown, often persisting well past the first season; abaxial leaf pubescence rusty red-brown, sparse to moderately dense, often giving surface a distinctly reddish hue; staminodes nearly as long as median corolla lobes; ovary densely pubescent; seed variegated; stomatal chamber openings located on raised, donut-shaped platforms
............ ..........12 Leaf vein reticulum evident but not boldly conspicuous, highest-order veins quaternary; stomatal chamber openings closed to a narrow slit, guard cells not visible through opening
............ ............ 13 Young twigs glabrous or nearly so, and abaxial leaf pubescence finely wooly; s. peninsular FL]
............ ............ ..14 Pubescence of leaves white, dense, woolly but matted, many of the trichomes straight and appressed; [se. to c. TX south to ne. Mexico]
............ ............ ..14 Pubescence of leaves red-brown to light brown to grey, moderately dense to sparse, woolly, the trichomes curled; [KS and OK south to c. and e. TX, and eastwards through MO, AR, LA, MS, and AL to FL and GA]