The middle and lower reaches of the Yangtze River have the eastern plain of China, which is also the area with the highest lake density in China. Five famous freshwater lakes in China-Dongting Lake, Poyang Lake, Taihu Lake, Hongze Lake and Chaohu Lake are all located here. This area is close to the ocean, located in the southeast Asian monsoon belt, with warm and humid climate, abundant precipitation, large area and many kinds of aquatic vegetation in the lake area. Aquatic medicinal plants in the lake are distributed in a regular ring from shallow coastal water to deep central water, followed by emergent plants, floating plants and submerged plants. Emergent plants refer to species whose roots are rooted in bottom mud and whose upper parts or Ye Ting are born on the water surface. Most of them are distributed in shallow water, shallow ponds, gullies and paddy fields in inner lakes. The main medicinal plants are reed, water candle, cattail, lotus flower, water chestnut, arrowhead, Alisma orientalis, Sparganum, Acorus calamus, Acorus gramineus, scallion and Curcuma tuber. Most of them are distributed in still waters such as lakes, ponds and gullies. The main medicinal species are Euryale ferox, water chestnut, wild water chestnut, duckweed, Manjianghong, Manjianghong, Yeping, Eichhornia crassipes, Alternanthera philoxeroides, water shield, water lily, Eupatorium adenophorum, water fern and Polypodiaceae. The main medicinal species are POTAMOGETON POTAMOGETON, POTAMOGETON POTAMOGETON, Ceratophyllum, Sargassum and Sophora alopecuroides. In addition, there are aquatic medicinal plants, such as rush, Pennisetum, arrowhead, Cynanchum stauntonii, amaranth and cress. The important cultivated medicinal materials in the lake area are Euryale ferox, Alisma orientalis, and water chestnut, water chestnut, lotus, water spinach and so on. Attach the following website: Correlation analysis between plant community characteristics and diversity index in the middle and lower reaches of the Yangtze River /onlineread/onlineread.asp? ID=88799 19。 Suid = egbnbfdhdncbcobobolgbopnpfp Plant Species Diversity Index of Agroforestry Complex Ecosystem in Three Gorges Reservoir Area/qk/96324x/199802/3181672.html.