Don't touch those fruits!

Among my favorite trees in Eureka Springs are the two ginkgo trees that flank either side of the back parking lot entrance of the Post Office.

Ginkgo has male and female flowers on separate trees. The two ginkgos at the Post Office are female trees, which means, of course, that they produce fruit. For most of the 20th century, ginkgos in American horticulture available at nurseries are male branches grafted on to rootstock. Why?

Ginkgo fruits notoriously smell like dog droppings, so they're fine as a shade tree along a sidewalk, but people don't exactly enjoy having them in their front yards. If you touch the foul-odored fruits with your bare hands, they will give you contact dermatitis just like poison ivy.

A few years ago, I was walking by the Post Office and saw a couple picking up the recently dropped ginkgo fruits.

"I wouldn't handle those with my bare hands," I warned.

"What? We have never heard of any problems."

They continued collecting and bagging the fruits. The next day the wife called me and asked if I knew how to treat dermatitis caused by handling fresh ginkgo fruits. The woman's red, irritated forearms looked like alligator skin. My only cure was the preventive measure I had suggested the day before.

Ginkgo seeds are considered edible in China. But, and that's a big but, only if you properly prepare them to remove the potentially toxic compounds. I had a botanist friend who was doing a wild food class at the Smithsonian. He stir-fried ginkgo seeds, demonstrating how to cook them to render them safe to eat, but as he explained the procedure, steam wafted toward his face. By the end of the class his eyes were swollen shut from the effect of the ginkgo seed toxins.

If you were an herbivorous dinosaur roaming the northern hemisphere several million years ago, you may likely have browsed on the leaves of the ginkgo tree, Ginkgo biloba. Ginkgo is a "living fossil." It is believed to have become extinct in the West during the Ice Age, but survived in China, which was largely unaffected by Pleistocene glaciation. It is the only surviving member of the Ginkgo family (Ginkgoaceae), and is the oldest living tree species on the planet.

Ginkgos, like cockroaches, have survived for more than 200 million years.