bristle-tipped teeth; inner bark yellow-orange Black Oak 26. Upper leaf surface glossy green 27 26. Upper leaf surface dull green, 7 to 9 lobes, 8 to 22 cm long, round sinuses extending less than half way to midrib Northern Red Oak 27. Leaves with 7 to 9 narrow lobes, sinuses extending more than halfway to midrib Scarlet Oak 27. Leaves with 5 to 7 narrow lobes, rounded sinuses, extending about three-fourths of way to midrib Shumard Oak _Species Described and Illustrated_ Mockernut Hickory _Carya tomentosa_ Nutt. [Illustration: silhouette] Bark grayish, tight, marked with distinct diamond-shaped ridges and furrows. Branches stout, drooping to spreading and ascending. Twigs 10 to 12 mm in diameter, conspicuous leaf scars. Buds (terminal) 10 to 15 mm long, 5 to 8 mm in diameter, scales imbricate. Leaves alternate, deciduous, odd-pinnately compound, 20 to 40 cm long with 5 to 7 drooping leaflets; yellow hairs and glandular hairs on lower leaflet surface, apex acuminate, margin finely serrate, base obtuse, on very short petiolules. Flowers unisexual, appearing in spring with developing leaves, staminate in 3-parted drooping catkins, pistillate terminal on new growth. Fruit subglobose to obovate, 3 to 5 cm in diameter, husk 1 cm thick, slow to open, shell of nut thick and hard, meat sweet. [Illustration: Mockernut Hickory/_Carya tomentosa_] Pignut Hickory _Carya glabra_ (Mill.) Sweet [Illustration: silhouette] Bark light to dark gray, often blackish, rough and deeply furrowed. Branches stout, drooping to spreading. Twigs 3 to 5 mm in diameter, reddish brown, smooth. Buds ovoid, acute, glabrous, 8 to 12 mm long, scales imbricate. Leaves alternate, deciduous, odd-pinnately compound, 20 to 40 cm long, usually with 7 leaflets; upper pair and terminal largest, 10 to 15 cm long by 4 to 6 cm wide, broadly oval to slightly obovate. Flowers unisexual, staminate in 3-branched catkins appearing about the time of leaf maturity; pistillate terminal on new growth. Fruit oblong to obovoid to obpyriform, 30 mm in diameter by 35 mm long, husk about 3 mm thick, tardily dehiscent, shell of nut thick, meat sweet. [Illustration: Pignut Hickory/_Carya glabra_] Shagbark Hickory _Carya ovata_ (Mill.) K. Koch