Ginkgo leaves. Leaves of the Chinese maidenhair tree, Ginkgo biloba. The two-lobed ginkgo leaf is unique among trees in that it has no midrib and no network of veins; rather the venation consists of a constantly branching fan of veins from the base of the leaf. This species of maidenhair tree is the only living representative of the ancient Ginkgoales (family: Ginkgoaceae). The tree is adaptable to almost any climate, and was introduced into Europe from China in the 18th century.