Stachybotrys chartarum is a greenish black cellulytic fungus that grows in wet low-nitrogen environments with high cellulose content such as hey, straw, wood chips, ceiling tile, drywall, wallpaper, insulation backing, and wood. This fungus can be a problem in houses that have suffered water damage. Stachybotrys produces mycotoxins such as macrocuclic trichothecenes and trichoverroids in its spores. Horses are especially susceptible to these toxins which can be ingested while eating infested hay. One mg of pure toxin can kill a horse. Stachybotrys has been implicated in fatal pulmonary hemorrhage and hemosiderosis in infants.