Here is a link to a story about an artist who paints ginkgo leaves to look like butterflies. You can see the “crenulated” hindwings akin to what VN describes
in his review of Audubon’s drawings.
http://big5.xinhuanet.com/gate/big5/local.xinhuanet.com/tp/2006-11/24/content_21912.htm
MR