Bark gray to blackish, thick, divided into flat ridges by deep furrows. Branches ascending, arching, and spreading; open-grown trees vase-shaped in outline. Twigs 2 to 3 mm in diameter with 5 to 7 leaves which increase in size from basal to apical leaf, red-brown. Buds (leaf) brown, small, scaly, acute. Leaves alternate, deciduous, simple; broadly ovate, 5 to 15 cm long, 4 to 6 cm wide; apex acuminate, margin usually doubly serrate, base oblique on short petiole; upper surface smooth, marked with sunken veins pinnately arranged; veins more prominent on underside. Flowers perfect, buds greatly enlarge before opening; with very small flowers abundant in clusters; opening before the leaves expand, blooming from late December into February. Fruit a samara, oval to circular with wing surrounding the seed, about 10 mm in diameter, margin ciliate. [Illustration: American Elm/_Ulmus americana_] Sugarberry; hackberry _Celtis laevigata_ Willd. [Illustration: silhouette] Bark light gray to almost white, thin, smooth, usually more or less studded with irregular corky outgrowths. Branches spreading, slender. Twigs about 3 mm in diameter, reddish-brown. Buds about 3 mm long, alternate. Leaves alternate, deciduous, simple; narrowly elliptic to broadly ovate, 6 to 10 cm long, 2 to 4 cm wide; apex acute, margin usually entire, base broadly rounded or oblique. Flowers unisexual or perfect, tiny, inconspicuous, many staminate and few pistillate appearing on the new growth as the leaves unfold. Fruit a drupe with a bony reticulated nutlet, about 5 mm in diameter, orange-red on a pedicel often shorter than the petiole of the subtending leaf. [Illustration: Sugarberry; hackberry/_Celtis laevigata_] Yellow-poplar _Liriodendron tulipifera_ L. [Illustration: silhouette] Bark thin and dark green on young trees, becoming ash-gray and conspicuously furrowed and ridged with age. Branches spreading to ascending, often drooping on large open-grown trees. Twigs smooth, about 5 mm in diameter, encircled by stipule scars, red-brown. Buds (terminal) grayish green, turning red in winter, flat about 10 to 16 mm long, scales valvate. Leaves alternate, deciduous, simple; dark green above, turning yellow in fall; 6 to 20 cm long and as wide as long; petioles 5 to 20 cm long, often longer than the blades on low branches. Flowers perfect, tulip-shaped, about 4 to 6 cm long, greenish-yellow with orange to reddish markings at base of petals, color intensifies with age. Fruit an aggregate cone, 5 to 8 cm long, gradually shattering into one-seeded, winged samaras. [Illustration: Yellow-poplar/_Liriodendron tulipifera_] Sweetbay _Magnolia virginiana_ L. [Illustration: silhouette]