Scrub Oak


Scientific Name: Quercus turbinella

Common Name: Scrub Oak
Family: Fagaceae, Scrub Oak family

Duration: Perennial
Size: 3 to 9 feet or so.
Growth Form: Shrub; Shrub or small contorted tree, tending to form thickets; bark light gray, rough, fissured; young twigs densely woolly, smooth, reddish-brown beneath the hairs; older twigs mostly hairless, gray, still more or less smooth.

Leaves: Evergreen, persisting 1-2 years; alternate and short-petiolate; blades oblong-elliptic to suborbicular, 1-5 cm long and 1-3 cm wide, 1.3-2 times as long as wide; margin with 1-8 pointed teeth; slightly gray-green on upper surface and dull green below; surfaces glabrous, or covered with stellate and glandular hairs when young and becoming glabrascent with age.
Flower Color: Monoeceous (male and female flowers on the same plant), minute, and lacking petals; male flowers in catkins 1-3 cm long, with 5-lobed calyx and 5-10 stamens; female flowers solitary, with a 6 lobed calyx and 3 styles. Fruits: Acorns solitary or several, elliptic, yellowish brown; with a scaly, shallow cup enclosing one-quarter to one-third of the nut.
Flowering Season: March thru June

Comments: Quercus turbinella reproduces sexually via its acorns if there is enough moisture, but more often it reproduces vegetatively by sprouting from its rhizome and root crown. You can often find galls on the leaves, petioles and twigs of Scrub Oak. These structures are produced by the plant in response to the internal feeding and chemical secretions of minute insect larvae. The responsible insect species are most commonly small wasps (cynipids) but may include moths, beetles, flies, or mites. The larvae are immature wasps, having arrived there when an adult female wasp (barely 2 mm long herself) inserted eggs into newly flushed leaves. Many of the galls are brightly colored and have received a lot of attention from ecologists and entomologists. Identifying the many kinds is made even more difficult due to the same species of wasp producing very divergent galls through the season and on different locations on the leaves, stems or buds.