Excerpts from Jim Conrad's
from the April 22, 2012 Newsletter issued from the woods of the Loess Hill Region a few miles east of Natchez, Mississippi, USA
OVERCUP OAK'S DISTINCTIVE LEAVES
At the swamp's edge stood some handsomely formed oaks who were easy to identify even though I couldn't find acorns or acorn cups below them. The leaves are shown above.
This is the Overcup Oak, QUERCUS LYRATA, a southeastern US tree specializing in growing on poorly drained, clayey bottomland soils subject to prolonged flooding. The leaves' distinctive field mark is the way the blades constrict for an inch or so right above their two bottom "ears." The blades are vaguely cross-shaped. Post Oaks and Bur Oaks have the most similar leaves, but Post Oaks occur on drier soils and Bur Oaks aren't found in this part of the world.
Overcup Oaks get their name from their peculiar acorns where the nuts are almost entirely enclosed in their cups.