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Wednesday, October 26, 2011

Crazy Plants: Ginkgo

Today's crazy plant is a living fossil.

A close up of the leaves of Ginkgo biloba.
Fossil Ginkgo leaf from the Eocene
I'm not kidding when I say that the gingko tree is a living fossil. 50 million years ago, the trees in this genus were really quite common in the temperate areas of the world. Now, G. biloba is the only species in the genus Gingko that is still living, and this is only due to the fact that a few individual trees survived in remote gardens in Asia. The fact still remains that this tree can only be found in cultivation, and if it weren't for us, it would have died out quite some time ago. Due to the unique shape of the leaves of the "maidenhair tree," it is a commonly used tree in landscaping. If you want one of these trees for your home, however, you better hope it isn't a female tree because the seeds of the ginkgo smell rather like vomit (or, as my source describes it, "rancid butter and gym socks"). By the way: yes, I have experience this smell first hand.

A ginkgo in autumn
The leaves of the ginkgo are fan-shaped and are often split into two lobes (thus the specific epithet biloba). The leaves grow in clusters on short branches. They are green in summer and become a beautiful shade of gold in the autumn. The leaf venation is unique for the overall shape of the leaf, what is termed dichotomous venation. Generally, fan-shaped leaves will be veined in one of three ways: palmate, parallel, or pinnate.

The closest living relatives of the ginkgo are the conifers and as such the ginkgo is classified as a gymnosperm (or non-flowering plant). This species is unusual among the gymnosperms due to the fact that it is dioecious (i.e. have separate sexes), with the male and female cones on separate plants. Seeds resemble cherries when fully mature. Though some would say the ginkgo has fruit, the fleshy outer coating that is seen is actually the seed coat.

Ginkgo seeds are actually eaten in parts of Asia, being sold with the odoriferous outer flesh removed.


Source is Bellevue College. Images are from Wikimedia Commons under creative commons licenses: one, two, three.

2 comments:

  1. Some time ago someone decided to plant a whole row of female ginko trees on Oregon State University's campus along a sidewalk. So you can not only smell them first hand, but step in the slippery piles of fruit, too. It is a rather unique opportunity, though.

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  2. Oh, wow! We only have one on our campus, and it's male. I really can't imagine what that must have been like.

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