Extract from Wikipedia article: Heterobasidion annosum is a basidiomycete fungus in the family Bondarzewiaceae. It is considered to be the most economically important forest pathogen in the Northern Hemisphere. Heterobasidion annosum is widespread in forests in the United States and is responsible for the loss of one billion U.S. dollars annually. This fungus has been known by many different names. First described by Fries in 1821, it was known by the name Polyporus annosum. Later, it was found to be linked to conifer disease by Robert Hartig in 1874, and was renamed Fomes annosus by H. Karsten. Its current name of Heterobasidion annosum was given by Brefeld in 1888. Heterobasidion annosum causes one of the most destructive diseases of conifers. The disease caused by the fungus is named annosus root rot.
Root rot fungus (polypore mushroom) Heterobasidion annosum(?) on a dry pine in Big Creek Scenic Area of Sam Houston National Forest. Shepherd, Texas, November 23, 2018 Big Creek Trail, Shepherd, TX 77371, USA
Pores of a polypore mushroom Heterobasidion annosum(?) in Big Creek Scenic Area of Sam Houston National Forest. Shepherd, Texas, November 23, 2018 Big Creek Trail, Shepherd, TX 77371, USA
Root rot fungus Heterobasidion annosum enveloping leaves and needles on a pine log in Big Creek Scenic Area of Sam Houston National Forest. Shepherd, Texas, January 19, 2020 Lone Star Hiking Trail, Coldspring, TX 77331, USA
Root rot fungus Heterobasidion annosum on leaves attached to a pine log in Big Creek Scenic Area of Sam Houston National Forest. Shepherd, Texas, January 19, 2020 Lone Star Hiking Trail, Coldspring, TX 77331, USA
Root rot fungus Heterobasidion annosum on bark of a pine log in Big Creek Scenic Area of Sam Houston National Forest. Shepherd, Texas, January 19, 2020 Lone Star Hiking Trail, Coldspring, TX 77331, USA
Texture of root rot fungus Heterobasidion annosum on a pine log in Big Creek Scenic Area of Sam Houston National Forest. Shepherd, Texas, January 19, 2020 Lone Star Hiking Trail, Coldspring, TX 77331, USA
Round patch of root rot fungus Heterobasidion annosum on a pine log in Big Creek Scenic Area of Sam Houston National Forest. Shepherd, Texas, January 19, 2020 Lone Star Hiking Trail, Coldspring, TX 77331, USA
Close-up of root rot fungus Heterobasidion annosum on a pine log in Big Creek Scenic Area of Sam Houston National Forest. Shepherd, Texas, January 19, 2020 Lone Star Hiking Trail, Coldspring, TX 77331, USA
White pores of root rot fungus Heterobasidion annosum on a pine log in Big Creek Scenic Area of Sam Houston National Forest. Shepherd, Texas, January 19, 2020 Lone Star Hiking Trail, Coldspring, TX 77331, USA
Root rot fungus (polypore mushroom) Heterobasidion annosum(?) on a pine log in Big Creek Scenic Area of Sam Houston National Forest. Shepherd, Texas, March 20, 2021 Lone Star Hiking Trail, Coldspring, TX 77331, USA
Resupinate polypore mushroom Heterobasidion annosum(?) on a pine fallen 3-5 years ago, growing on the lower surface, in Big Creek Scenic Area of Sam Houston National Forest near Shepherd. Texas, December 21, 2021 Lone Star Hiking Trail, San Jacinto County, Texas, United States
Close-up of resupinate polypore mushroom Heterobasidion annosum(?) from a fallen pine in Big Creek Scenic Area of Sam Houston National Forest near Shepherd. Texas, December 21, 2021 Lone Star Hiking Trail, San Jacinto County, Texas, United States
Texture of resupinate polypore mushroom Heterobasidion annosum(?) from a fallen pine in Big Creek Scenic Area of Sam Houston National Forest near Shepherd. Texas, December 21, 2021 Lone Star Hiking Trail, San Jacinto County, Texas, United States