HARBIN -- Researchers have found a large number of Aldrovanda vesiculosa, an endangered species commonly known as waterwheel plants, in a wetland in Northeast China's Heilongjiang province, local authorities said Friday.

Researchers from universities and Qixinghe National Nature Reserve identified more than 5,000 waterwheel plants scattered in an area of over 600 square meters in the reserve during an observation tour between Sept 20 and 23, according to the provincial forestry department.

Waterwheel is a rootless and free-floating plant, like an aquatic Venus flytrap. It was under class one national protection in 1999 and listed as an endangered species by the International Union for Conservation of Nature.

"Waterwheel plants have strict requirements for water, which needs to be shallow, warm and extremely clean," said Yao Yunlong from the Northeast Forestry University, which participated in the research.

Yao said the discovery showed a better local environment driven by China's stronger ecological protection. The Chinese leadership are emphasizing ecological protection, demanding an increase in the size of forests, lakes and wetlands.

China boasts 577 nature reserves and 468 wetland parks. The push for preservation has gone as far as becoming part of the criteria for assessing local government officials in some regions.

Waterwheel plants are found in Europe, Asia, Africa and Australia. In China, it only spreads in Heilongjiang. Yao said they first found this species in 2015 in a wetland in the province but only a small quantity.