Molds of this genus first gained public attention because of their association with lung diseases in infants and very elderly people. The incidents are rare but have occurred throughout the United States.
These species generally are observed in bathrooms and lavatories, in crevices between tiles and seams between walls and floors. Sometimes the appearance of such may be a misidentification of other materials.
If a resident or homeowner is experiencing allergic symptoms or notices a black discoloration in the areas described, it is strongly recommended that a mold inspector be hired to conduct the appropriate sampling to determine the exact nature of the material.
Generally speaking, if the testing demonstrates that the material is a species of Stachybotrys, what is seen on the surface is an indication of a much greater problem. Do not take unnecessary chances. Have the testing performed by a qualified mold inspector.