Alternaria alternata
 
It is a rapidly growing fungus that produces a greenish-black colony within five days, when incubated at 25°C (77°F) on microbiological media (Malt Extract Agar).  The hyphae, conidiophores, and conidia are pigmented olivaceous-brown (dematiaceous). It is found worldwide and is very common.  It can be isolated from air, plants (including causing "black spot of roses"), foodstuffs, soil, and textiles.

Photograph by Dr. Rajiv Sahay ©2008 EDLab at Pure Air Control Services

Rarely an opportunist human pathogen causing a hypersensitivity pneumonitis (woodworker's lung disease), and an immediate-type hypersensitivity - type 1 (IgE-mediated) extrinic asthma and disease that is very common in individuals with atopic disease.