Ginkgo is one of the oldest living tree species. The extract of ginkgo leaves is used medicinally in North America, where it’s one of the most popular medicinal herbs, and many other countries around the world. In traditional Chinese medicine, the seeds of the ginkgo tree are used. (Cathy Wong, in an article on About.com)
Alternative medical information abounds on the Internet. Here are two sources I like the look of: http://nccam.nih.gov/health/ginkgo/ and http://www.healthy.co.nz/ailment/2007-ginkgo-biloba.html.
This lush and lovely example of ginkgo biloba is growing on Lambton Quay in downtown Wellington.