Fomes is a genus of perennial woody fungi in the family Polyporaceae. Species are typically hoof-shaped (ungulate). New growth each season is added to the margin, resulting in a downward extension of the hymenium. This often results in a zonate appearance of the upper surface, that is, marked by concentric bands of color.
The name comes from Latin fomes, meaning "tinder", from the use of Fomes fomentarius, also known as the tinder fungus, in making tinder (see amadou).
Taxonomy
Fomes was first introduced by Elias Magnus Fries as a subgenus of Polyporus in his 1836 work Genera Hymenomycetum. He promoted it to generic status in 1849.
Description and ecology
Fomes species have perennial, hoof-shaped fruit bodies that attach directly to their substrate without a stipe. The cap surface has a hard smooth crust that ranges in colour from gray to blackish. On the underside of the cap, the pore surface is pale brown with small pores, and brown tube layers. The tough and fibrous context is pale brown. The fruit body becomes stratified after multiple years of growth. Fomes has a trimitic hyphal system, containing generative, skeletal, and binding hyphae. The generative hyphae have clamp connections, while binding and skeletal hyphae have pale brownish pigment that appears when they are mounted in a solution of potassium hydroxide. The cystidioles are fusoid, imbedded, or project somewhat. The basidia (spore-bearing cells) are club-shaped with a basal clamp, and have four sterigmata. The spores are cylindric, large, hyaline and smooth, and are non-reactive to Melzer's reagent.
Fomes fungi are among the food recorded for the pleasing fungus beetle genus Megalodacne. A possible Fomes (but the identification was very uncertain) was also once recorded in association with the little-known pleasing fungus beetle Haematochiton elateroides; however, it is suspected that these beetles were not feeding on the fungus, but simply hibernating in the dead log on which it grew.
