Tylopilus

Tylopilus is a genus of mushroom-forming fungi in the family Boletaceae. It contains a large number of described species and is distributed worldwide, with many species found in temperate forests. Members are bolete mushrooms, meaning they have a cap and a spongy hymenophore of tubes (pores) beneath the cap rather than gills, and they typically form ectomycorrhizal associations with trees.

Morphology: Fruit bodies are variable in size and color but share a common structure: a convex to depressed cap with a smooth to scaly surface; a pale to brown pore surface that darkens with age; and a stout stem that may be colored or reticulated and often lacks veil remnants. The flesh is usually white to yellowish and generally does not blue when cut. The spore print is olive-brown to brown. Many species show local color changes in the pores or flesh as they age or bruise.

Ecology and distribution: Tylopilus species are primarily mycorrhizal partners of conifers and hardwoods, appearing in forests during the warmer months to autumn depending on climate. They are more common in temperate zones but occur in tropical regions as well.

Notable species and caution: The genus includes species with bitter tastes, and some are considered inedible. The best-known example is Tylopilus felleus, the bitter bolete, which is poisonous and can resemble edible look-alikes. Because taste testing is unreliable and misidentification can be dangerous, reliable identification should rely on multiple characters and local field guides.