(Ginkgo biloba) The only surviving member of an ancient order of conifer-like trees that covered the earth during the Jurassic period, 150 million years ago. Ginkgo grows slowly to more than 50 feet tall. Its leaf is shaped like a duck’s foot, and is unlike any other leaf in the world. Ginkgo trees are either male or female. The females won’t fruit without pollination from a male. The ripening fruit has no aroma, but if left to rot it has an unpleasant rancid smell. Planting any single tree will mean you have no pollination and therefore, no fruit. The edible nuts are green with a white shell and are the size of a small almond. The nuts, a delicacy in Asia, are roasted, steamed or boiled. The nuts and leaves are used in Chinese herbal medicine to increase blood flow to the brain. And we almost forgot to tell you that ginkgo is used to stimulate memory. Ginkgo grows in a wide variety of soils and is a pollution tolerant tree. In the fall, the leaves of both the male and female turn a glorious golden yellow. USDA Zones 4-9.