Deli, a perennial herb, is wild in wetlands. It can't sow, and it can bear fruit without cultivation and keep it underground. Moreover, the flood will not die, and the drought will not die, and it will never stop planting. Every spring, when the water depth and temperature are suitable for growth, it germinates in the soil, grows stems and jumps out of the water. Its stem is spherical and its leaves are slender and prismatic, and each plant can grow 4-5 leaves. Many fibrous roots can be born in the lower part, and the root system is developed. Each plant can bear several pears, and many can bear more than 10. Pears are small in size, generally more than 1 cm in diameter, and large ones can grow to about 2 cm. The skin color is black, the meat is white, and it contains more starch and sugar. It can be eaten raw or ground, which is a good substitute for food. Tripterygium wilfordii can be extracted from the upper leaves of Pyrus mollissima, which can be as high as 1 meter, and as high as 2 meters. The top of Pyrus mollissima has several small horns with seeds the size of sesame seeds in them. When it matures in autumn, it will collapse into the mud with the grass or drift into other places with the wind. When it is suitable for its growth, it will grow tiny Pyrus mollissima seedlings, which is another form of propagation of Pyrus mollissima.