Which Oak?

Earlier this week Jamie and I spent some time working in west Kentucky mapping the boundaries of wetlands.  

Some of the wetland boundaries were easy to see, as they were dominated by a tall reed called Phragmites austraulis, which is considered a noxious and invasive plant.   This reed is very aggressive, and sends out long runners that can reach as much as thirty feet in a single year.  Where this plant gets a foothold, it's nearly impossible to control.  

Navigating through reeds that are nearly twelve feet tall was a challenge, but Jamie would put his back to it and push a path through the stems.  We tried to stay on the beaver trails when we could.  

The wetlands that weren't open and sunny reed beds, were dominated by trees.  Mostly common species like red maple, green ash, sweet gum, and river birch, but occasionally we would find oak trees, like this one.  What kind of oak is it?  

The leaves that we could find on the ground under the trees were jagged on the margin, like a chestnut tree, but chestnuts don't grow in wetlands.  

The cups on the acorns were large.  The bark was a light color, and seemed flaky.  

I think there are nearly eighty species of oak tree in the United States, but thankfully my Trees and Shrubs of Kentucky book only lists nineteen types of oak, and based on the description I think the trees we were seeing were swamp chestnut oak (Quercus michauxii). 

When I look on the USDA plant database website, and zoom in on the range map for swamp chestnut oak, I can see that the green counties of occurrence are clustered in western Kentucky.  So, we were in the right part of the state, the photo of the leaf looks right, the description of the bark "light gray and scaly" fits our observations, the habitat "wet flats, and other moist ground" is spot on, and we saw lots of sweet gum trees in the area, which is listed in the book as an associate species.  Bingo.  It's a swamp chestnut oak!