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Monday, April 28, 2014

Ginkgo biloba - Ginkgo Tree

Ginkgo biloba is a really beautiful and interesting tree with a long history. Often called a living fossil because it was growing before the dinosaurs. It is the only living relative from that period. Ginkgo's are not flowering plants but a gymnosperm, more closely related to pine trees than oaks. There is a Ginkgo Petrified Forest just out side of Vantage Washington. Trees are reported to live for 3500 years or so.

Ginkgos form large trees, growing to 100' but in cultivation and as a street tree may reach 50'. Cultivated varieties have pretty decent shapes, but the species can have main lateral branches going almost any direction, so the form is not very clear or formal, though they are upright for the most part. There were two trees on the WSU campus that were propagated from weak lateral branches and developed into a weak side lateral branch habit referred to a plagiotropism.

If you google Ginkgo biloba, you will see pages and pages of ginkgo extract used for medicinal purposes.

Two large trees at Wisley Garden.

Large tree in Chico CA.

Leaves are deciduous, simple, with a distinct shape, alternate on elongating stems, appearing whorled on spurs. The leaf has two lobes, most of the time but can be seen looking somewhat like a whale's tail. Generally 2-4" long, with a dissection in the middle of the tip being deep or virtually non existent. Looking like a maidenhair fern leaf. I used to think the name biloba was because of the leaf, but its not, see below. I suspect that more people know a ginkgo leaf than any other leaf. I see all sorts of ginkgo leaf art.

More deeply lobed leaf.

Even more deeply lobed from Portland

The venation is key, its dichotomous, and the only plant I have heard of with such a pattern. It is like a bracket in a sporting event, maybe you have seen tennis tournament brackets, or the NCAA basketball brackets but not squared off, like a Y in a road. Essentially the veins branch into two equal veins, these branch the same and it goes on and on, so the leaf starts off thin, and gets wider like a fan.

Wonderful fall color, bright yellow, and in cold climates they seem to all fall at the same time.

Young trees showing great fall color but also their awkward growth habit.

Plants are dioecious, male and female and you want the males. Males produce catkin looking stroboli while the females produce a short reproductive structure with 2 lobes (hence the name, biloba).

Males in a "catkin like" structure.

Female trees develop a fleshy cone like structure. After they ripen and fall they produce butyric acid, which smell like someone else's vomit. Unfortunately they are not reproductive for 25 or so years, so its too late to pull it out (buy named cultivars). Fleshy, edible, used for centuries as a medicinal crop.

Downtown Santa Cruz sidewalk.

Bark is pretty, deeply fissured looks sort of like cork with age.

Misidentification: Not a chance.

1842 Calypso Dr.

124 Central Ave - Vary large specimen.

Santa Cruz
Clock tower, cultivar Saratoga, with great fall color, nice pyramidal habit and a male,

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