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Key to Rhamnaceae

Rhamnaceae

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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.
             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).
                   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 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 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]
                            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