The Wikipedia article.
Grinling Gibbons is carved from basswood, or lime, as it is known in England.
The wood is useful as a secondary cabinet wood; its flowers produce a high grade honey; basswood is considered to have medicinal qualities, and the name "bass" is derived from "bast", a product of the inner bark, which native Americans used to make rope.
It is a large tree, growing wild and as a cultivated street tree.
Addenda: A large basswood in the tree lawn a block over from my home.