March 06, 2009
The photo above shows an august ginkgo tree (Ginkgo biloba) in Frederick, Maryland. It's one of the oldest and largest ginkgo trees in the U.S. The impressive specimen shown here has a circumference of nearly 14 ft (4 m), a height of 93 ft (28 m) and a spread of 92 ft (28 m)! Ginkgos are among the longest living deciduous trees – this one evidently sprouted in 1827. Another fascinating thing about ginkgos is that wild populations are extremely rare. Ginkgo biloba, is the only living representative of the order Ginkgoales, which is native to eastern Asia and has a heritage of more than 250 million years. Before the last ice age, 10,000 years ago, there were ginkgo forests in North America and Europe as well as Asia. In a curious departure from the usual extinction story, the ginkgos that are here today, even in Asia, owe their existence to human intervention. Engelbert Kaempfer, a German botanist, was the first Westerner to describe the ginkgo which he found in cultivation at Buddhist monasteries in Nagasaki, Japan in 1691. They prefer sunlight to shade but aren't too choosy about soil type. Extracts from ginkgo leaves are widely sold as herbal medications to help treat circulatory disorders and to boost memory.