2b. Tall shrub, with leaves broadest below or near the middle (early summer) =Wahoo, Evonymus atropurpureus.= STAPHYLEACEAE, the Bladder Nut Family Shrubs with opposite trifoliate leaves and small axillary clusters of white flowers in spring; sepals, petals, and stamens each 5; ovary 3-celled, ripening into a large inflated 3-celled pod. One species in Michigan (2-5 m. high) =Bladder Nut, Staphylea trifolia.= ACERACEAE, the Maple Family Trees or shrubs, with opposite, lobed or compound leaves and inconspicuous flowers; sepals about 5; petals the same number, or none; stamens 4-12; ovary 2-lobed, ripening into a pair of winged fruits. 1a. Leaves compound (tree; flowers appearing before the leaves) =Box Elder, Acer negundo.= 1b. Leaves simple (Maple) --2. 2a. Shrubs or small trees; leaves 3-5-lobed; the lobes with regularly serrate margins (flowers greenish-yellow, appearing later than the leaves) --3. 2b. Trees; leaves 3-7-lobed; margins of the lobes entire or incised, but never regularly serrate --4. 3a. Leaves finely and sharply serrate; twigs smooth; bark conspicuously striped with white lines =Striped Maple, Acer pennsylvanicum.= 3b. Leaves coarsely and bluntly serrate; young twigs pubescent; bark not striped =Mountain Maple, Acer spicatum.= 4a. Angles between the leaf-lobes rounded (flowers greenish-yellow, appearing with the leaves) --5. 4b. Angles between the leaf-lobes acute or obtuse, but not rounded (flowers purple, red, or yellowish, appearing before the leaves) --6. 5a. Leaves glabrous beneath, or minutely pubescent on the veins =Sugar Maple, Acer saccharum.= 5b. Leaves downy beneath =Black Maple, Acer saccharum var. nigrum.= 6a. Middle leaf-lobe usually more than half the length of the leaf, narrowed at its base; broken twigs with a strong odor =Silver Maple, Acer saccharinum.= 6b. Middle leaf-lobe usually less than half the length of the leaf, its sides parallel or broadened at the base; broken twigs without strong odor =Red Maple, Acer rubrum.= SAPINDACEAE, the Soapberry Family Trees, with opposite palmately compound leaves, and showy white or yellowish flowers in panicles in spring; sepals 5; petals 4 or 5; stamens about 7; fruit a smooth brown nut. 1a. Leaflets 7; buds viscid; corolla of 5 petals =Horse Chestnut, Aesculus hippocastanum.= 1b. Leaflets 5; buds smooth; corolla of 4 petals =Buckeye, Aesculus glabra.= BALSAMINACEAE, the Touch-me-not Family