Xylobolus

Xylobolus is a genus of crust fungi in the family Stereaceae. These fungi are characterized by their resupinate growth habit, meaning they grow flat and closely adhered to the surface of their substrate, typically dead wood.

Description: Xylobolus species typically form thin, leathery or crust-like fruit bodies that can be quite extensive. The surface is often smooth to slightly bumpy and can vary in color, ranging from pale brown and tan to reddish-brown or orange-brown. Microscopically, Xylobolus is defined by the presence of gloeocystidia (specialized cells containing oily or resinous substances) and encrusted cystidia (sterile cells with crystalline deposits). The spores are smooth, hyaline (translucent), and generally ellipsoid in shape.

Habitat and Distribution: Xylobolus species are saprobic, meaning they obtain nutrients from decaying organic matter. They are commonly found on dead branches and logs of hardwoods, particularly oak and other deciduous trees. The genus has a widespread distribution, occurring in temperate and tropical regions around the world.

Taxonomy: Xylobolus was originally described by Elias Magnus Fries in 1849. The classification and phylogenetic relationships within the genus are still being studied and refined using molecular data.

Distinguishing Features: Distinguishing Xylobolus from other crust fungi can be challenging and often requires microscopic examination. The presence of gloeocystidia and encrusted cystidia is key for identification. Macroscopically, the color and texture of the fruit body, along with the substrate on which it is growing, can provide clues.

Notable Species:

• Xylobolus frustulatus: A common species characterized by its irregular, cracked appearance and often found on oak.