Chinkapin oak (Quercus muehlenbergii) is a native oak which is often not recognized as an oak when first encountered. It does not have lobed leaves like most other oaks; its leaves are toothed like a chestnut. Like all oaks, it does have a cluster of buds at the end of branches.
Habitat: Grows on rocky slopes and exposed bluffs. Commonly fount in the east and southwest Iowa.
Hardiness: Varies with the species of oak tree ranging from zone 3 to zone 9
Growth Rate: Slow to Moderate
Mature Shape: Broad, rounded
Height: Varies with species. Often maturing between 50 to 75 feet tall. Capable of growing upwards of 100 feet.
Width: 40 to 70 feet. Varies with species
Site Requirements: Best growth in moist, well-drained soils. Adaptable to adverse soil conditions.
Leaves: Alternate, simple, lobed; lobes with rounded tips
Flowering Dates: May - June
Seed Dispersal Dates: September - October
Seed Bearing Age: 15 years
Seed Bearing Frequency: Yearly
Seed Stratification: No stratification period is needed.
Chinkapin oak is a medium sized tree (1 to 2 feet in diameter and 40 to 70 feet tall). It is native over all of Iowa except for the northwest one-quarter of the state. Although native, chinkapin oak is sporadic within its range and seldom is a dominant species in a woodland. Its common associates include white oak, bur oak, black oak, ironwood, redcedar, and the hickories. Chinkapin oak prefers well drained soils along bottomlands or on limestone ridges bordering streams where it grows best. It is commonly found on dry bluffs, ridge tops, and rocky, south facing slopes.
Its leaves are simple, alternate, 3 to 6 inches in length and 11/2 to 3 inches wide, with 8 to 13 pairs of veins and an equal number of large, sharply pointed teeth. The leaves are thick, firm, light yellow green above and lighter green to silvery white below. The acorns are 1/2 to 3/4 inch long, without a stalk; the caps are bowl shaped covering 1/3 to 1/2 of the acorn. Twigs are greenish tinged with red or purplish red, turning orange brown to gray brown later in the year. The bark is quite thin, breaking into plate-like scales similar to white oak.
Chinkapin oak is normally a tree, but on very dry and/or on soils with low fertility, it will become shrubby. Small chinkapin oaks can be confused with dwarf chinkapin oak (Quercus prinoides); dwarf chinkapin oak has smaller leaves with 3 to 7 pairs of veins and teeth and shorter petioles. The issue is even more confusing where the two species are growing together because they hybridize easily, resulting is stands of shrubby oaks with some of the characteristics of both species.
The wood of chinkapin oak is hard, heavy, strong, durable and shock resistant. Because the tree is relatively rare, its wood is normally sold as white oak.
Chinkapin is not used extensively as an ornamental tree, although it is quite tolerant tougher sites. It develops as a tree with an open, rounded crown, attaining heights of 40 to 50 feet.