|Gliocladium species are common and are most closely related to Penicillium and Paecilomyces. No cases of infection have been reported in humans or animals. Information regarding toxicity is sparse. Gliotoxin is produced primarily by Trichoderma virens, Aspergillus fumigatus, and a few less common Penicillium species, rather than Gliocladium. Allergenicity has not been well studied. May be identified on surfaces by tape lifts, tease mounts from bulk samples, and in air by culturable (Andersen) samples. (Spores do not have distinctive morphology and might be categorized as "other colorless," Penicillium/Aspergillus, or Trichoderma on spore trap samples, depending on the age and condition of the spores.) Gliocladium is found very infrequently in air samples because the spores are formed in sticky masses and are not easily disseminated by air currents. Widespread in decaying vegetation and in the soil.