Cao Yunquan takes a photo of Tongjian No 1. [Photo provided to nantong.gov.cn]

Cao Yunquan, aged 86, recently donated valuable documents and over 600 books to Daiwuqiao community in the Chongchuan Economic Development Zone in Nantong.

Daiwuqiao will build a bookstore called Grandpa Cao for local residents to read the books and documents free of charge.

Documents record Cao's research findings on plants. [Photo provided to nantong.gov.cn]

Cao, who is also renowned for his efforts to protect ancient plants in Nantong, said that some of these books were inherited, some collected during study and work, and some given to him by friends.

Cao introduces his books and documents. [Photo provided to nantong.gov.cn]

The documents are results of Cao's decades of investigation and research into plants. For example, over the past decade, he has been studying Gossypium arboreum var. obtusifolium, a species of cotton also known as Tongjian No 1, which has received recognition from the Ministry of Agriculture and Rural Affairs.