The tulip tree (liriodendron tulipifera or commonly canary whitewood) has rounded leaves that are quite unusual. They turn buttery yellow in the autumn. The tree with the flowers is opposite the lake, near the arbour.
It likes lime free soil in sun or partial shade and reaches up to 12 metres
Folklore: “When Adam and Eve were marching out of Eden having been banished, Eve spitefully tugged at the leaf of the tulip tree. In so doing she pulled off the central lobe, triggering all future tulip trees to grow without them” (http://www.plant-lore.com/tulip-tree/)
It has a history of use as a tonic and treatments for fever in the Southern Appalachians. It has also been used to treat gangrene and inflammation by native Americans.