Smithsonian Gardens

Common name: Chestnut Oak, Basket Oak, Rock Oak

Family: Fagaceae (Beech)

Distribution: S Illinois to E USA

Habitat: Mixed hardwood and conifer forests on rocky slopes; 0-1400m

Hardiness: -30 - 20 F

Life form: Deciduous tree

Average height: 50-70'

Bloom Time: April

Fall color: Red, orange, yellow-brown

Foliage characteristics: Alternate, simple leaves are obovate with toothed margins. Leaves are green above, grayish below, and 4-6" long.

Fruit characteristics: Acorns are 1-1.5" long with a warty cap that covers 1/3-1/2 of the nut. They mature in the fall in one growing season, and seperate from the cap.

Structure: Round

Bloom characteristics: Flowers are yellow-green catkins which appear in late spring.

Bark characteristics: Dark and furrowed, with distinctive v-shaped ridges.

Ethnobotanical uses: Acorns can be eaten, although tannis will need to be leached if bitter.

Description: This oak and Q. michauxii were previously both described as Q. prinus, and are often still confused for each other. Chestnut oaks are long-lived trees which filled the gap left in eastern American forests once the American chestnut was all but wiped out in the early 1900s. Now, Appalachian forests are dominated by swamp chestnut and chestnut oaks, as well as several other types of oaks. This oak has some of the largest acorns of the American oaks, and can be eaten by humans if not bitter.
This tree is considered threatened in Illinois and Maine.