X. nigricans X. sporodochifer Xyleborus is a genus of lichen-forming fungi in the family Stereocaulaceae.

[1] The genus was circumscribed in 2009 by Richard C. Harris and Douglas Ladd with Xyleborus sporodochifer assigned as the type species.

[2] A second species, X. nigricans, was added to the genus in 2015.

[3] This genus is only found in North America, in the Ozarks, the Appalachians, the Mid-Atlantic Coastal Plain, and in Kansas.

[3] Xyleborus species only grow as a crust with black apothecia on weathered logs and stumps in intact forests.