Margins distinctly toothed 14 14. Teeth obtuse or rounded, leaf base wedge-shaped, stellate pubescent below Chestnut Oak 14. Teeth sharp 15 15. Leaves normally elliptic, veins prominent below, bases rounded; corky outgrowths on older branches, often lacking on large trees Winged Elm 15. Leaves broadly oval, pinnate veins distinct, margins doubly toothed, bases oblique, unequally rounded American Elm 16. Leaves palmately lobed 17 16. Leaves pinnately or apically lobed 18 17. Leaves opposite, more or less glaucous and pubescent below; fruit a double samara Red Maple 17. Leaves alternate, glabrous below; fruit spherical, woody with spine-like projections; corky outgrowths on branches frequent Sweetgum 18. Blades truncate to notched at apex, 4-lobed; fruit an aggregate of samaras; flower conspicuous, greenish-yellow with red markings Yellow-poplar 18. Blades with acute to obtuse apices 19 19. Blades apically 3-lobed 20 19. Blades pinnately lobed 21 20. Blades broadly obovate, base rounded, rusty pubescent below Blackjack Oak 20. Blades narrowly obovate, base wedge-shaped, mostly glabrous Water Oak 21. Leaves with rounded lobes 22 21. Leaves with bristle tips to lobes and lateral teeth 23 22. Leaves with 7 to 9 lobes, divided nearly to the midrib, whitish below White Oak 22. Leaves with 5 unequal lobes, upper lateral pair larger, squarish, at right angles to midrib, crosslike in appearance, pubescent below Post Oak 23. Leaves pubescent below, whitish to tawny 24 23. Leaves glabrous below or with a few hairs on midrib and in vein axils 26 24. Leaves with 7 to 9 lobes, terminal lobes long, strap-shaped, slightly curved, bases bell-shaped Southern Red Oak 24. Leaves with 7 to 11 lobes 25 25. Leaves oblong, 7 to 11 lobes, base broadly wedge-shaped to truncate, secondary lobes rare; inner bark reddish Cherrybark Oak 25. Leaves broadly oval, 7 to 9 lobes, each lobe with secondary