A small, button-shaped, white fruiting body of Heterobasidion root disease, <i>Heterobasidion annosum</i>, with a penny placed nearby for size scale.
A small, button-shaped, white fruiting body of Heterobasidion root disease, Heterobasidion annosum, with a penny placed nearby for size scale.
Credit: Joseph Obrien, USDA Forest Service, Bugwood.org
Licensed under a Creative Commons Attribution 3.0 License