Wolfiporia cocos

About

Wolfiporia extensa, commonly known as hoelen, poria, tuckahoe, China root, fu ling, or matsuhodo, is a species of fungus in the family Polyporaceae. It is a wood-decay fungus but has a subterranean growth habit. It notably develops a large, long-lasting underground sclerotium resembling a small coconut.

Summary from Wikipedia