Ohio Buckeye (Aesculus glabra var. glabra)

4/20/12 Port Penn, DE. Buckeye is in the Horse Chestnut family.
This leaf looks more like Buckeye than Horse Chestnut.
Buckeye: http://plants.usda.gov/java/profile?symbol=AESCU
Horse Chestnut: http://plants.usda.gov/java/profile?symbol=AEHI
Update 6/18/15:
- broad pyramidal clusters of yellowish or greenish-yellow flowers
-Petals only slightly unequal in size, and stamens about 2x as long as petals
http://www.namethatplant.net/gallery_comparison.shtml?compare=flowers%20of%20Buckeye%20species
see also:
http://wisplants.uwsp.edu/scripts/detail.asp?SpCode=AESGLAvGLA