Cao Yunquan reads a children's book with two boys at the Grandpa Cao Bookstore. [Photo/Nantong Daily]

Cao Yunquan, aged 87, recently donated more books and documents to Grandpa Cao Bookstore in Chongchuan district's Daiwuqiao community.

Grandpa Cao donated 400 children's books and documents about valuable trees to the bookstore this time and last year he donated valuable documents and over 600 books, leading to the establishment of the Grandpa Cao Bookstore.

Cao Yunquan introduces the books he donates. [Photo/Nantong Daily]

Cao is renowned for his efforts to protect ancient plants in Nantong. 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.