(2) Metasequoia glyptostroboides: deciduous trees, with a height of 35 meters and a DBH of 2.5 meters. The lateral branches are opposite and pinnate. The leaves are strip-shaped, flat, and 1.3 mm ~ 20 mm long, alternately paired to form two rows, which are pinnate. The cone is drooping, nearly quadrangular spherical or short cylindrical, about 18 mm ~ 25 mm long. Produced in Sichuan, Hubei and Hunan. Found in 194 1 year, it is a rare tree species unique to China.
(3) Davidia involucrata: also known as water pear. Deciduous trees, 15m ~ 20m high. The leaves are broadly ovate, the apex is acuminate, the base is heart-shaped, and the edges are serrated. Spherical head with two ivory bracts at the base, oblong or oval, about 7 cm long and 3 cm ~ 5 cm wide. Endemic to China, distributed in Sichuan, Guizhou and Yunnan. When flowering, white bracts cover the treetops, just like a flock of pigeons, so it is also called "China pigeon tree". World famous ornamental plants.
(4) Ginseng: a perennial herb. 30 cm to 60 cm high. Spindle-shaped or cylindrical fleshy roots, short stems, palmately compound leaves, three to six rounds. Flowers are small, yellow-green, umbels. Fruit oblate, red. Produced in northeast China, North Korea and other places, it has excellent medicinal value and is one of the "three treasures of Kanto".
(5) Ginkgo biloba: commonly known as Ginkgo biloba, or Gongsun Shu. It first appeared in the Carboniferous period 345 million years ago and was widely distributed in Europe, Asia and America in the northern hemisphere. It was the king of the world like dinosaurs in the animal kingdom. By 500,000 years ago, the Quaternary glacial movement occurred, the earth suddenly became cold, and most ginkgo plants were on the verge of extinction. Only when China has superior natural conditions can it miraculously survive. Therefore, scientists call it a "living fossil" and a "panda in the plant kingdom".
Ginkgo biloba leaves, in particular, cannot be brewed with tea and chrysanthemum. Ginkgo biloba contains a lot of ginkgolic acid, which is toxic. Generally, the leaves bought are not extracted by deep processing, and the ginkgolic acid content in them is as high as 3000-4000ppm. In particular, ginkgolic acid is water-soluble. Instead of eating the effective substances such as ginkgo brass and ginkgolic acid, the effect is the opposite, and it is full of poison!
In medicine, especially in ginkgo products used in hospitals, slight ginkgolic acid containing 10ppm is allowed!
(6) Taiwania flousiana: It is a rare and precious tree species in the world and only grows in Myanmar, Taiwan Province Province, Hubei, Guizhou and Yunnan. It is a protected plant in China. It was first discovered in 1904 at an altitude of 2000 meters in Wuzunkeng, the central mountain range in central Taiwan Province Province.
Taiwania flousiana is an evergreen tree with spreading branches and slender drooping branchlets. Up to 60 meters high and 2-3 meters in diameter. It slowly grows to 40 meters high. Dense branches, small crown and fibrous bark. The leaves on the branches are arranged in a spiral shape. Strangely, the leaves on the small tree are different from those on the old tree. The leaves on the young trees are sharp, shovel-shaped, large and flat, while the leaves on the old trees are scaly and rhombic. Seen from the cross section, they are triangular or quadrilateral, and there are stomatal lines on them. Taiwania flousiana is a monoecious spherical flower plant. 5-7 male cones are borne at the top of branches. Female cones are smaller than male cones and are also planted on branches. The growing cones are oval without scales, and the bracts are inverted conical to rhombic. Its seeds are only about 5 mm long and its wings are very narrow.
Taiwania flousiana grows at an altitude of 1800-2600 meters in the mountains of central Taiwan Province Province. Scattered in Platycladus orientalis and Sabina vulgaris, it is also found at the junction of northwest Yunnan and Lichuan and Enshi counties in Hubei Province. The top of the tree is slightly curved, with more than 30 small stamens and 36 seed scales. Many Taiwania flousiana have also been found in Guizhou province. Most of them are distributed in Leishan, Taijiang, Jianhe and other counties around Leigong Mountain, the main peak of Miao Ling Mountains. In the patches of Taiwania flousiana forest, many of them are towering old trees over 100 years old, reaching as high as 30 to 40 meters.
Taiwania flousiana is an important timber tree species in Taiwan Province Province. Its trunk is straight, the wood hardness is moderate, the texture is delicate, the heartwood is purple-red-brown, and the sapwood is dark brown and reddish, which is easy to process. It is a good material for buildings, bridges and furniture. In addition, it is a good tree species for timber forest, scenic forest, water source forest and street trees.
Taiwania flousiana belongs to Taiwania of Taxodiaceae. It has only one "twin brother"-Taiwania flousiana. Because of their similar appearance, they are distributed in the same area and are generally called Taiwania flousiana. But they are still different. The leaves of Taiwania flousiana are narrower than Taiwania flousiana, and the seed scales of cones are more than Taiwania flousiana. Although they are rare tree species, the number of Taiwania flousiana is relatively small. Therefore, Taiwania flousiana is listed as a national first-class protected plant, and Taiwania flousiana belongs to the second category.