Quercus polymorpha, the Mexican white oak, Monterrey oak or netleaf white oak, is a North American species of oak. It is widespread in Mexico, Guatemala, and Honduras, and known from a single population in the United States (about 30 km north of the Río Grande in Val Verde County, Texas) but widely planted as an ornamental.Quercus polymorpha is a subevergreen tree up to 20 meters (67 feet) tall. Bark is gray or brown.