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1 Leaves 1-pinnately compound, > 10 cm long, not fascicled on short spur shoots; stems not spiny; leaves evergreen.
..2 Leaves entire; flowers solitary or 2-4 in umbels; spines mostly simple; [section Tschonoskyanae]
....3 Leaves evergreen, coriaceous; leaf teeth tipped with firm prickles; fruits blue-black, pruinose; [section Wallichianae]
......4 Leaves with 1-9 (20) bristles on each margin, the bristles 3-6 mm apart; berries ovoid (6-9 mm long, 6-7 mm broad), 5-10 (rarely more) in an often umbellate raceme; petals notched at apex; [section Canadenses]
......4 Leaves with 18-36 bristles on each margin, ca. 2 mm apart; berries ellipsoid (8-10 mm long, 4-5 mm broad), 10-20 in a raceme; petals obtuse at apex; [section Vulgares]