Ginkgo biloba first appeared in the Carboniferous period 345 million years ago. Ginkgo biloba was widely distributed in Europe, Asia and America in the northern hemisphere, widely distributed in the northern hemisphere in Mesozoic and Jurassic, and began to decline in the late Cretaceous. Until 500,000 years ago, the Quaternary glacial movement occurred and the earth suddenly became cold. Most ginkgo plants are on the verge of extinction. They are extinct in most parts of Europe, North America and Asia. Only China has superior natural conditions, which have been miraculously preserved. Therefore, it is called "living fossil" and "giant panda in plant kingdom" by scientists. There are still wild Ginkgo biloba in China, northern Xuzhou, Jiangsu, southern Linyi, Shandong and mountainous areas in western Zhejiang. Due to the scarcity of individuals, dioecious plants will be replaced by the remaining forests if natural regeneration is not strictly protected and promoted. Most distribution areas of Ginkgo biloba belong to artificial cultivation areas. Mainly planted in China, French and South Carolina. There is no doubt that foreign Ginkgo biloba was introduced directly or indirectly from China.
Ginkgo trees are tall and straight with fan-shaped leaves. The canopy is large and cool, which has a cooling effect. The leaves are quaint and have a long life. Strong adaptability, Ginkgo biloba has extensive requirements for climate and soil. Ginkgo biloba is a tall tree with straight trunk, beautiful posture, green in spring and summer and golden in late autumn. It is an ideal tree species for landscaping, roadside, highway, field forest net and windbreak belt, and is listed as one of the four long-lived ornamental tree species (pine, cypress, Sophora japonica and ginkgo biloba) in China.
China is not only the hometown of Ginkgo biloba, but also one of the countries and regions with the earliest cultivation, utilization and research and the richest achievements. Throughout the ages, China ranks first in the world in terms of ginkgo planting area and ginkgo output. Judging from the age of the existing ancient ginkgo trees, ginkgo was planted between Shang and Zhou Dynasties in China.
Ginkgo biloba is a unique and rich economic plant resource in China. Seed coat can be extracted with tannin extract; The wood is light yellow, thin, light and soft, and it is used in architecture, furniture, sculpture and other handicrafts, as well as garden trees and street trees. Seeds contain hydrocyanic acid, histamine acid, protein, etc. Seeds and leaves can be used as medicine in traditional medicine in China. They are flat, bitter and slightly toxic.
morphological character
Ginkgo biloba is a deciduous tree with a height of 40 meters and a DBH of 4 meters. The bark of young trees is nearly smooth, light gray, and the bark of big trees is grayish brown, with irregular longitudinal cracks, long branches and short distances, and slow growth. Leaves alternate, scattered radially on long branches, 3-5 clusters on short branches, slender petiole, fan-shaped, light green on both sides, wide top edge notched or 2-lobed, 5-8 cm wide (~15), and multi-branched veinlets. Dioecious, sparsely coextensive, cones solitary in leaf axils of short branches; Male cones are inflorescence-shaped, each with many stamens and 2 anthers; The female cone has a long stalk and the stalk end is often bifurcated (3-5 forks). At the fork end, 1 ovule with disc-shaped suspensor is produced, and often 1 ovule develops into a developing seed.
The seeds are drupe-shaped, long-stalked, pendulous, oval, oblong-obovate, ovoid or nearly spherical, 2.5 ~ 3.5 cm long and 65438 0.5 ~ 2 cm in diameter; The aril is fleshy, covered with white powder, and pale yellow or orange yellow when mature; Testa bony, white, usually with 2 longitudinal edges; Endosperm membranous, reddish brown.