Stachybotrys is a genus of molds, or asexually-reproducing, filamentous fungi. Closely related to the genus Memnoniella, most Stachybotrys species inhabit materials rich in cellulose. The genus has a widespread distribution, and contains about 50 species.

The most infamous species, S. chartarum (also known as S. atra) and S. chlorohalonata are known as “black mold” or “toxic black mold” in the U.S. and are frequently associated with poor indoor air quality that arises after fungal growth on water-damaged building materials.