Thursday, April 19, 2007

Ginkgo Biloba

Ginkgo biloba is a survivor. The dinosaurs knew this tree, which has been on the planet for 150 million years, perhaps much longer. It is the oldest known tree species.
The common name, maidenhair tree, derives from the resemblance of the tree’s foliage to that of maidenhair fern. The delicate foliage turns a lovely, clear yellow in the fall.

The tree is much tougher than the common name suggests. Municipal tree departments love it because it is pollution tolerant, low-maintenance, and quite free of pests and diseases. Homeowners, dog walkers, and passersby are generally less enthusiastic. The reason: ginkgos typically have a ungainly habit (form) in youth. With age, however, they develop a craggy beauty. I have seen ginkgos in Japanese temple gardens that are 1000 years old, yards wide at the base, and majestic. The trees are said to survive for millennia.
Plainfield has numerous ginkgos, most quite young. There is a large female ginkgo at 810 Central Avenue just to the left of the driveway, about 50 feet back from the sidewalk. It is 38 inches in diameter at breast height (dbh) and is estimated to be more than 100 years old, a young adult.

There is also a smaller female in the curbside strip directly in front of the building. Both trees litter the ground with prodigious quantities of powerfully malodorous fruit each fall. In general, only male ginkgos are planted in the U.S. because of the unpleasant odor produced by the females' fruit. Mistakes happen, however, so female ginkgos are not hard to find. Some Eastern cultures use the ginkgo seeds in cooking. In my neighborhood people can be seen gathering the seeds each fall from the ground below the female ginkgos on Watchung Avenue near Hillside. They use only the kernel, leaving the stinking seed coat where it fell. Some theorize that the stench of the seed coat evolved as a defense against seed-eating dinosaurs, but the tactic doesn't work against humans.

The street trees surrounding the Plainfield Library illustrate the ungainly habit of young ginkgos quite well.

The old ginkgo in the parking lot on the westbound side of the tracks at the Netherwood train station used to be a majestic presence. Sadly, it was inexpertly pruned (brutally hacked) in about 2004, each of its branches having been cut back to a 5-6 inch diameter stump. The tree is 48 inches dbh and is estimated to be more than 150 years old.

One last tidbit intended to motivate you to plant a ginkgo in front of your own house: Ginkgo biloba is a nonconformist. Among its oddities is its unusual sex life, which features swimming sperm. Ginkgos are among the few living things to have survived in close proximity to the Hiroshima atomic bomb blast. The tree is different enough from other extant plants that scientists have assigned it its own phylum. Recalling high school biology, the hundreds of thousands of members of the plant kingdom are divided into 12 phyla. One of those phyla consists of just a single species: Ginkgo biloba. The tree is the last remnant of an almost vanished tribe that represents an entirely different way of being a plant. Ginkgo biloba is a survivor.

Coming: Dawn redwood. I know of only four dawn redwoods (Metasequoia) in Plainfield, and only one of those is easily visible from the street. If you are aware of any notable dawn redwoods in town, please let me know, and I will try to include them in an upcoming posting.

Copyright Gregory Palermo