Water oak is a medium-sized tree with glabrous twigs, membranous leaves, and a straight, slender trunk.
Water oak is monoecious.
It bears seed by age 20, and production is good on alternate years. Germination is hypogeal and occurs in the spring following maturation. Because of a generally late spring emergence, seedling mortality from flooding is low. The seedlings do not tolerate prolonged submergence. Because of the large seed, young seedlings have high initial survivorship regardless of available light, drought stress, or herbivory.