Quercus similis, the swamp post oak or bottomland post oak, is an oak species native to the southeastern and south-central United States. The greatest concentration of populations is in Louisiana and Arkansas, Mississippi, and eastern Texas, with isolated population in Missouri, Alabama, and the Coastal Plain of Georgia and South Carolina.
Quercus similis is a deciduous tree up to 25abbr=offNaNabbr=off tall. It has a straight trunk. The bark is brown and flaky. The branches are gray, and between NaNsp=usNaNsp=us in diameter. The leaves are between 8and long and 5to wide, more or less closely egg-shaped. The apex is acute or rounded, base shortly indicated. The leaf margins are flat with two or three pairs of shallow lobes apical half, shiny dark green on top but gray underneath between 3 and 5 pairs of veins. The petiole is between 3 and 10 mm long. The flowers appear in spring. The acorns are between 1.2and long, oblong, and dark brown. It produces acorns one at a time or in groups of three.