Quercus lyrata aka Swamp Post Oak

Quercus lyrata, or overcup oak, belongs to the white oak group. This deciduous tree grows wild in the central and southeastern United States. Its range reaches Texas, Florida, New Jersey, and the Mississippi valley. It lives in floodplain woods, swamps, and other low ground. Garden trees reach 40–60 feet [12–18.29 metres] tall. Their crowns can spread to 60 feet [18.29 metres]. The trunk often grows straight beneath a broad, round crown. Some trees have a twisted form instead. Young crowns can be oval or shaped like pyramids.

This oak grows slowly and sheds its leaves each year. Its dark gray bark has deep grooves and scaly plates. Young gray twigs have hairs that fade with age. The leaves grow one at a time along the stems. Each leaf has five to nine deep, round lobes. The upper side shines dark green. Fine hairs cover the gray-green lower side. Fall leaves may turn yellow, brown, or red. Small brown buds gather at the ends of twigs.

Small flowers appear in spring and add little show. In North Carolina, bloom runs from March through April. Chicago lists bloom dates that extend into May and June. Male flowers hang in long catkins. Each tree also bears female flowers. The acorn cup wraps around most of the nut. This gives the tree its name and helps acorns float. Acorns ripen each year, reaching maturity in September and October in North Carolina. Trees start making seeds at about 25–30 years old.

Full sun suits this tree best, though it accepts partial shade. It grows well in acidic loam that stays moist or wet. It also handles clay, poor drainage, and brief floods. Sites with better drainage can suit it too. Sources place its hardiness in USDA zones 5–9. It needs little upkeep and suits lawns or low ground. Its crown provides shade, while birds and small mammals eat acorns. Moth and butterfly larvae feed on this oak. Deer cause some damage, but the tree has mild resistance. People also use its wood for fuel.

Possible pests include scale, borers, leaf miners, and nut weevils. Oaks can develop root rot, leaf spots, cankers, and mildew. NC State reports that this species resists oak wilt. Its acorns can cause poisoning and block the gut. Plants For A Future describes cooked seeds as food after removing bitterness. That use requires preparation and does not make raw acorns safe.