Toxic mould spores (Stachybotrys chartarum), computer illustration. Several strains of this fungus (S. atra, S. chartarum and S. alternans) are synonymous. This fungus may produce a trichothecene mycotoxin (Satratoxin H) which is poisonous if inhaled. The toxins are present on the fungal spores. The toxins produced by this fungus will suppress the immune system affecting the lymphoid tissue and the bone marrow. The spores will die readily after release but the dead spores are still allergenic and toxigenic. Inhalation of spores (conidia) may also induce pathological changes (pneumomycotoxicoses).