Evergreen tree. Most of them are tall trees. 20-50 meters high, up to 75 meters (American sugar pine P. lambertiana). Very few are shrubby, such as Pine pine (P.pumila) and Pine pine (P.yunnanensis). The pine tree is a round branch with long internodes, thin, straight or slightly curved branchlets, and slender needles in bundles. Therefore, its canopy looks fluffy and not compact, and the word "pine" is the image description of its canopy characteristics. Therefore, "pine" is a kind of tree with a canopy. The pine tree is strong and does not die all the year round.
Morphological characteristics
The crown of the tree is pyramid-shaped when it is young, and the branches are mostly in the shape of a wheel. After the seedlings are unearthed and the cotyledons are unfolded, the primary leaves are the first to grow, solitary, arranged in a spiral, linear lanceolate, with teeth on the leaf margin. The primary leaves perform the function of leaves for 1 to 3 years before the needles appear, usually in bundles of 2, 3, 5, and are born on the tops of short branches. There is a leaf sheath at the base of each bundle of needles, which is sheathed early or persists. The position of resin ducts in mesophyll tissue is relatively constant in adult plants, and can be divided into three types: exophytic, mesophytic, and endophytic. One or two vascular bundles can be seen in the cross-section of pine needles, and vascular bundles may merge in double-vascular pine trees under special circumstances. Ball flowers unisexual, monoecious. Most of the cones are composed of seed scales, which become lignified after maturity. The exposed and thickened part of the seed scale is called the scale shield, and the tumor-like protrusion at the tip of the scale shield is called the scale umbilicus. Some tree species have thorns on the scale navel, while others do not. When the cones mature, the scales open and the seeds fall off; however, the scales of a few trees remain closed for a long time. Each scale has 2 seeds, the upper part of the seed has a long wing, and a few have short wings or no wings.
Red pine (P.koraiensis), Pinaceae is the largest family of gymnosperms, with 10 genera and more than 230 species, of which there are more than 90 species of Pinus, which is the largest genus of Pinaceae and the entire gymnosperm phylum . Pine trees are the most important forest tree species in the northern hemisphere. Except for Sumatra pine which is distributed to 2 degrees south latitude, the rest naturally grow in the mountains and fields from the equator to 72 degrees north latitude. Especially in temperate regions, there are not only many species of pine plants, but also often form vast forests, so pine trees are known as the "mother of forests in the northern hemisphere". Pine trees are highly adaptable to terrestrial environments. They can tolerate low temperatures of -60°C or high temperatures of 50°C, and can grow in bare mineral soils, sandy soils, volcanic ash, calcareous soils, limestone soils, and various soils from podded soils to red soils, and are resistant to drought and barrenness. , like the sun, so it is a famous pioneer tree species. The most obvious feature of pine trees is that the leaves are needle-shaped, often in bundles of 2, 3 or 5 needles. For example, the leaves of Chinese pine, masson pine, and Huangshan pine are bundled with 2 needles, the leaves of white bark pine are bundled with 3 needles, and the leaves of Korean pine, Huashan pine, and five-needled pine are bundled with 5 needles.
Pine trees are monoecious plants, and the sporophytes are arranged in cones to form male and female cones. Female cones are single or 2-4 are born at the top of new branches, and most of the male cones are gathered at the lower part of new branches. The cones of pine trees generally open in spring and summer, but after the pollen is passed to the female cones, they will not germinate until early summer of the second year, fertilizing the female flowers and developing into cones (commonly known as pine cones or pine cones, not fruits). The cones mature after autumn, the scales are open, and each scale has two seeds.
Most species in the genus Pinus are tall and straight trees with good materials and many pillars. Northeast China's "King of Wood" - Korean pine, tall tree species (up to 75 meters) widely distributed in western North America - Ponderosa pine, native to the coast of California, the fastest growing pine tree - Radiata pine, native The slash pine in the southeastern United States, the Caribbean pine native to the American Caribbean, and the European scotch pine widely distributed in the west and north of Eurasia are all famous timber species.
The ornamental value of pine trees is obvious to all. In China, pine trees can be seen from the royal classical gardens to the homes of modern residents, such as Chinese pine and white bark pine in Beijing Beihai, the Summer Palace, and five-needle pine widely used in tree stump bonsai. The pine is strong and the pine is famous for its mountains. The Huangshan pine in Huangshan, the Huashan pine in Huashan, and the beautiful pine in Changbai Mountain... all of them are amazing for tourists.
oldest pine tree
On the east side of Chengguang Hall in Tuancheng, Beihai Park, Beijing, there is a Chinese pine tree, which is more than 800 years old. When Emperor Qianlong saw that it was shaded by the sun, he named it "Shade Marquis". In the Songshan Natural Forest Park in Yanqing County, Beijing, there are ten scenic spots in total, and the "primitive pine forest" is one of them. There is a "Pine King" in the forest, with a diameter of 76 cm, which has lived for more than 500 years.
On the eastern edge of the Ordos Plateau in Inner Mongolia and in the loess hills and valleys on the west bank of the Yellow River, there grows an ancient ancient pine, which is 25 meters high, 134 centimeters in breast height, 14.5 x 16.4 meters in crown width, and 13. cubic meters in volume. The tree is nearly 900 years old and is known as the "king of Chinese pine".
There is an ancient pine tree on the cliff at the back cave of Nanshan Temple in Guixian County, Guangxi Zhuang Autonomous Region. The tree is more than 3,000 years old and is considered to be the oldest pine tree found in my country so far. Although it has experienced wind, rain, cold and heat, it has always been vigorous and upright, lush and lush. There are three characters of "not old pine" engraved on the cliff. Tourists go to visit and often take photos with ancient pine, taking it as a symbol of longevity.