black mold

noun

: any of various greenish-black molds of the genus Stachybotrys (especially Stachybotrys chartarum synonym S. atra) that are found especially on water-saturated cellulose materials (such as cardboard, fiberboard, or dust)

Toxins from mold—such as those from an infamous black mold called Stachybotrys, which is often cited in lawsuits as causing grave harm to human health—are not readily airborne, and are therefore not likely to be breathed in.

—Christopher Wanjek, The Washington Post