What are the characteristics of the latest ginkgo trees?

The branches of ginkgo biloba are tall and straight. Bark lobed, grayish when young. With the aging of the tree, the cracks and color gradually become darker. There are obvious differences in crack shape and length among plants. From strip to cross, the length ranges from 40 cm to 100 cm.

Ginkgo biloba can be more than 30 meters high and more than 3 meters in diameter at breast height. Under suitable conditions, ginkgo biloba can grow into high-quality wood with straight trunk, perfect trunk and small sharpness. The suitable ecological environment is the basis to ensure that ginkgo biloba grows into high-quality wood with small sharpness. Ginkgo biloba on the West Tianri Mountain in Lin'an County, Zhejiang Province, is accompanied by tall trees such as golden pines, and the mountain humus soil is loose and fertile, so the plant grows more vigorously and the trunk is straight, at least ten meters long from the ground, almost as thick as up and down. The 90-year-old adult tree has a height of 23-26 meters and a volume of about 1 cubic meter, and is still in the peak period of volume growth.

Ginkgo biloba, which is in the state of isolated wood, and ginkgo biloba distributed to the north (such as Liaoning) or south (such as Guangdong), the height of the branches on the trunk is less than 2 meters, and there is a great disparity in the thickness of the trunk, especially in the backbone branches of the branches. This is due to the inhibition of plant growth by various factors. The backbone branches, which are nearly whorled, sometimes greatly inhibit the growth of the trunk. Although this situation is extremely disadvantageous to the production of high-quality wood, it is beneficial to the flowering and fruiting of the plant.

The xylem of Ginkgo biloba is composed of circular tracheids with marginal holes. In some parenchyma cells, there are large calcium oxalate crystals with red appearance, extremely underdeveloped rays and obvious annual rings. The cortex of Ginkgo biloba is thicker, with small diamond-shaped or oval lenticels, the outer skin is generally strip or block-shaped cracking, slightly with varying degrees of intersection.

There are a lot of hidden buds on the trunk of ginkgo biloba. The short branches sprouted from these hidden buds can sometimes blossom and bear fruit. Under certain conditions, these hidden buds will also develop and expand, forming rows of tumor-like protrusions. At the base of the main branch or at the bend of the big branch, this protuberance is stalactite, commonly known as "nipple", "silver milk" or "tree milk". The largest milk seen is more than 2.0 meters in length and more than 28 centimeters in diameter at the base (Guizhou). At the base of the trunk, this bulge expands horizontally to form a tumor, which is called a "chair" by the masses. Sometimes rows of verrucous processes arranged horizontally can be seen on the trunk, which are also developed from the adventitious buds of ginkgo biloba. It is different from tree milk in that it is not obviously oriented to the ground. The mechanism of this bulge is not clear, and it may be related to the inhibition of plant growth.

Both female and male plants of Ginkgo biloba can produce milk, but the proportion of female plants is significantly higher than that of male plants. Therefore, among the masses, there is a saying that "ginkgo biloba can bear fruit only if it has tree milk and chairs." In fact, not only big trees can grow milk, but even one-or two-year-old seedlings, or even buds that have just been sown for two months, can grow small nodules below the rhizome under blocked root growth or other specific conditions; on the contrary, not all adult ginkgo biloba trees that have entered the fruiting stage can grow tree milk. Therefore, there is no basis for saying that the formation of tree milk is a sign of entering the fruiting stage. Whether it is possible to make early identification of the fruiting and other characters of Ginkgo biloba from the degree of difficulty of producing milk is also worth doing some in-depth study.