Ginkgo biloba is the last survivor of a disappeared family of trees,
It is an alive fossil of 150 million years!
The name Ginkgo (or Gingko) comes from the Chinese name yin kuo, which means silver fruit.
Ginkgoaceae belong to the class of the cordaites (or Ginkgophytes),
subset of the prespermaphytes, which grew in the whole world between the
primary era and the secondary era. They constituted one of the links between
the ferns and the flowering plants (the angiosperms or magnoliophyta).
|It was discovered into 1690 in Japan by the German botanist Engelberg
It is originating in the Far East, of the south-east of China. The buddhist monks venerated it, and undoubtedly them its survival is owed.
Regarded as guard to entreat fire, it was planted near the pagodas, in the imperial gardens in China, wood crowned of the temples.
One of its vernacular names is: Tree of the pagodas.
It is introduced in Europe in XVIIIth century, in the Netherlands in
1727, then in England in 1754. A rich person ship-owner of Montpellier
in France could acquire a foot of it, in 1788, in England, for the extravagant
sum of forty ecus. This is why, one of its vernacular names is: Tree
with the forty ecus.
Being able to reach a height from 30 to 40 meters, it presents an irregular crown. The male subjects have a hurled form, the female subjects are a more compact form. The trunk is divided into several large drawn up branches; the ramifications ascending then are spread out with the years.
|The deciduous leaves have a fan-shaped on more or less
corrugated margin. They are joined together in clusters at the end of a
rather long petiole on the side short boughs, insulated on the long boughs
where they are alternate.
The shape, a little trapezoidal, whose veins are radiant, is indented in its middle, and forms two lobes. The notch is deeper at the female subjects.
The leaf is long 5 to 8 cm, coriaceous, light green, then dark green for finally transfering to the luminous yellow in autumn.
|The buds are conical and brown; the wide base is entirely inserted on the short and alternate side boughs.||The initially greenish boughs become gray brown. They carry very tight foliar scars.|
The flowers are always fixed on the short boughs, and appear in May
April. It is a dioecious species; there is a male tree and a female tree.
|The male flowers are yellowish catkins joined together by 2 to 5 in long clusters from 4 to 7 cm in long at the end of the side boughs. Many stamens are established according to a loose layout.|
|The female flowers are bare, without floral parts, grouped per pairs, or three, or, insulated, lengthily pedunculate, green, forked at the end, claviform, equipped with two free ovules.|
The reproduction is carried out by mobile male gametes which reach the female gametes while moving actively in water. It is a zoidogamy, a primitive watery fecundation.
The fecundation has place inside an ovule, stuffed protective body of
substances of reserve which makes it possible the embryo to be nourished
and to be protected.
|The fruit is an ovoid drupe from 2 to 3 cm in diameter, with pulpy
pericardium, lengthily petiolate. In autumn, from October to November,
intervenes its maturity; it breaks up quickly and then releases a strong
rancid butter odor. This odor is haveed to the butiric acid that it contains.
It has the taste of an almond.
|In autumn, the foliage of Ginkgo biloba takes a gold yellow color of
the most beautiful effect. It is a very beautiful ornamental tree, insensitive
with the air pollution, little requiring from the soil, but preferring
a wet soil. Rustic, it prefers a hot moderate climate. Photophilic, it
will have to profit from a good sunny exposure.
Its growth is slow. It reaches its adult age around thirty years. But its longevity is considerable. We know specimens of more than thousand years.
Except its decorative and sacred uses, it is exploited in pharmacology.
It is regarded as the leader as phlebotonic, in phytotherapy. It improves
arterial and venous circulation, cerebral and peripheral.
It is used also in the sickness of Alzheimer.
Copyright © 2000-2017 Loic de Kermadec, Florence Dautry. All rights reserved.