A few corrections about Ginkgo......
This gymnosperm species, (Ginkgo biloba), (thus, by definition, a softwood, even though it doesn't actually bear cones) has rather soft, sometimes brittle, light-colored wood, without much figure, that is quite distinct anatomically. I have not heard of the wood itself giving off an odor (in my experience it does not), unpleasant or otherwise. It is used occasionally for flat work, but I've not turned it, nor have I heard of others using it for turning. I also would be interested to learn of its suitability for projects on the lathe. To provide more information about ginkgo, and to correct some common misconceptions about it, read on.....
Ginkgo is a dioecious tree species, meaning that there are male and female plants. Being a gymnosperm, the tree does not "flower" but produces more primitive reproductive structures: The male produces a short branched structure which allows pollen (produced in anthers) to disperse into the wind; The female plants produce paired 'cone-like' structures which capture the pollen and enable seed to be set. The so-called ginkgo "fruits" are not fruits at all, but are simply seeds with fleshy seed coats. These seeds produce an offensive, smelly compound (butyric aid) that is what the 'stink' is all about. (Some botanists hypothesize that the production of the smelly odor by the seeds was to attract plant-eating dinosaurs and other animals to aid in the ginkgo's dispersal.) The ginkgo has been around for at least 150 million years, and is the sole survivor of a plant lineage with several species that was found throughout Europe, Asia, and North America; I have fossil specimens of ginkgo species from Nebraska!
Because the seeds produce this offensive odor, male plants are often deliberately chosen for horticultural plantings so that the seeds are not produced when the tree reaches maturity. Female trees are not as desirable for plantings, although in certain Asian cultures the seeds are collected, roasted and eaten. Natural chemical products found in the leaves (ginkgo flavonoids) have been found very effective in promoting blood circulation and increasing memory/learning efficiency. Of all trees capable of surviving in urban planting settings, none has surpassed the ginkgo in its tolerance to the harshness of sidewalk plantings, drought, disease, and air pollution. To avoid future "messes" by female plants, those planting ginkgo trees will even pay a premium for 'certified' male trees that have male upper parts (scions) grafted to a rootstock, instead of taking the chance of getting a female tree if purchased as 'standard' seed-produced seedling trees.
Perhaps more than you wanted to know about ginkgo - one of my favorite trees to talk about in lecture....fortunately, there is no exam at the end of this post!
Cheers,
(Prof.) Rob Wallace
Iowa State University
