CHANGCHUN, Oct. 22 (Xinhua) -- A book on wetland plants in northeast China has been published.

The two-volume book, with 1.28 million words and color photos, depicts more than 700 varieties of wetland plants including their names, appearance, distribution areas and economic value.

It is believed to be the first comprehensive book on wetland plant resources in northeast China, which includes the provinces of Liaoning, Jilin and Heilongjiang.

Its author Zhou You, a life sciences researcher at Tonghua Normal University in Jilin Province, had traveled more than 200,000 km to visit hundreds of wetlands over the past 30 years, collecting over 5,000 specimens and taking around 200,000 photos of plants.

"The book provides scientific proof and references for the research of wetland plants in northeast China and even the Northeast Asian region," said Liu Xingtu, an academician with the Chinese Academy of Sciences.

Wetlands play a crucial role in water purification, flood control, and maintaining bio-diversity. China has more than 600 wetland nature reserves and over 1,000 national wetland parks.