American holly (Great Smoky Mountains National Park

American holly

Ilex opaca

Summary ⁶

Ilex opaca, the American Holly, is a species of holly, native to the eastern United States, from coastal Massachusetts south to central Florida, and west to southeastern Missouri and eastern Texas.

Description ⁷

This single-trunked tree is typically 30-60' tall at maturity, forming a rounded pyramidal crown from a dense network of short crooked branches. On older trees, trunk bark is light gray, shallowly furrowed, and warty, otherwise it is light gray and more smooth. Branch bark is also light green and relatively smooth. The bark of both trunk and larger branches is often discolored from lichens. Twigs are gray or brown and smooth, while young shoots are light green to tan and either glabrous or hairy. Evergreen alternate leaves occur along the twigs and young shoots. The leaf blades are 2-4" long and ¾-2" across; they are broadly elliptic or ovate and shallowly lobed (pinnatifid). The lobes and tips of the leaf blades terminate in sharp spiny teeth. The upper blade surface is yellowish green or green and somewhat shiny, while the lower surface is more pale and dull; both sides of the blade are hairless. The texture of the leaf blades is stiff and leathery. The petioles are short, light green, and often pubescent. American Holly is dioecious, forming male (staminate) and female (pistillate) flowers on separate trees. Male trees produce axillary clusters of 3-12 male flowers on peduncles about 1" long. Individual male flowers are about ¼" across, consisting of a short green calyx with 4 lobes, 4 greenish white or yellowish white petals, and 4 stamens. Female trees produce female flowers individually or in groups of 2-3 (rarely more). Individual female flowers are about ¼" across, consisting of a short green calyx with 4 lobes, 4 greenish white or yellowish white petals, 4 residual stamens that are infertile, and a green pistil. The petals of both male and female flowers are oblong in shape. The peduncle and pedicels of the flowers are green and either hairless or sparsely pubescent. The blooming period occurs during late spring or early summer for about 3 weeks. Cross-pollination between a male tree and a female tree is required in order for the latter to set fruit. Fertile female flowers are replaced by drupes that become mature during the fall. Mature drupes are about 1/3" across and either bright red or orange-red (rarely yellow). The fleshy interior of each drupe has a bitter taste. This tree spreads by reseeding itself.