@rabbitazteca23

11 months ago

China's plant life is enormously rich. Some 31,000 plant species are native to China, representing nearly one-eighth of the world's total plant species, including thousands found nowhere else on Earth. By comparison, the United States and Canada combined contain about 20,000 native plant species. China is the only country on Earth where there are unbroken connections among tropical, subtropical, temperate, and boreal forests. This unbroken connection has led to the formation of rich plant associations rarely seen elsewhere in the world. Many genera of plants which are known only from fossil records in North America and Europe are represented in China by living members. China also has the most diverse flora of any country in the North Temperate zone. Similarities between the plants of China and North America Mainland China and the continental United States share a common latitude and similar-sized land areas. The climates in much of the two regions are also similar, especially in the eastern halves. Many plant species that were once widespread throughout the entire northern hemisphere were wiped out by glaciation in North America but survived in China. Nearly 120 genera in 60 families of plants have disjunct populations in eastern Asia and temperate North America, relicts of the once widespread flora. Knowledge of the Chinese flora is essential to understand floristic composition and interpret the fossil records of Europe, North America, and temperate Asia. Many genera (e.g., Ginkgo, Metasequoia, Pseudolarix, Cercidiphyllum) which are known only from fossil records in North America and Europe, are extant in China. Metasequoia is one of the best known examples of taxa that were once widespread but now have very limited distributions. This genus was first known only from fossil remains and was thought to be Sequoia. In 1948, soon after botanists recognized it as a new genus (Metasequoia), a stand of living trees was discovered in central China. This genus, which once covered Asia, Europe, and North America, is now represented in the wild by only about 5,000 individuals in China. Cultivated trees outside of China have been grown from seeds sent to the West in 1947, including some given to and flourishing at the Missouri Botanical Garden and the Arnold Arboretum of Harvard University. They are elegant reminders of the past shared by the floras of Asia, Europe, and North America. The use of plants by the Chinese Throughout their centuries-old tradition, the Chinese discovered and adapted native plant resources for use as food, spices, and medicine. Several thousand species of Chinese plants are now cultivated throughout the world, including short-grain rice, tea, soybeans, oranges, cucumber, lemons, peaches, apricots, ginger, anise, and ginseng. Hundreds of Chinese species (e.g., rhododendrons, magnolias, camellias, viburnums, gardenias, jasmines, forsythias and primroses) are cultivated as ornamentals worldwide. The Flora of China will provide a ready means of understanding, locating, and using these plants. Nearly 5,000 species of plants are used for medicine in China today, a fact that is of increasing interest to western medical researchers and pharmaceutical companies. Two examples: first, Trichosanthes kirilowii, a member of the gourd family found only in China, is being studied by medical researchers for its strong activity against HIV, the virus that causes AIDS. Second, the Chinese populations of Artemisia annua, which is a member of the sunflower family, show great promise against drug-resistant Plasmodium falciparum malaria. Some 250 million people around the world contract malaria each year. Only the drug derived from Artemisia annua appears to be effective against all strains of the malaria parasite.

5 |