Rapidly growing fungi that produce pigmented colonies that are some shade of green, yellow, brown, or black within ten days, when incubated at 25oC (77oF). It is very common worldwide. It can be isolated from air, plants, foodstuffs, soil, sand beaches, caves and mines, activated sludge, mangrove swamps, freshwater, compost, animal dung, silage, fodder, and cotton fabrics in the tropics. Some species are thermotolerant. Some species are allergenic and other species produce powerful mycotoxins. They are one of the most common causes of systemic fungal disease in humans and animals causing primarily acute or chronic respiratory tract infections.