Ulocladium (you-low-clay-dee-um) is a genus of saprophytic, darkly pigmented fungi.  Ulocladium  species are cosmopolitan and are commonly found in the soil and on decaying herbaceous plants, paper, textiles, dung, emulsion paint, grasses, fibres and wood. 

In buildings, Ulocladium is commonly found in damp or wet areas such as bathrooms, kitchens and basements and around windows. It is frequently isolated from painted surfaces, damp wall finished with wallpaper or water based emulsion paint; floor and mattress dust. It grows on very wet walls and particleboard. Because of its high water requirements it is considered an excellent indicator of water damage.

Ulocladium has two known species; Ulocladium chartarum and U. botrytis.

U. chartarum is the species most commonly found in indoor environment. Its presence in indoor environment together with other molds such as Stachybotrys, Fusarium and Chaetomium is an indication of water damage.

Ulocladium has been reported to cause Type I (hay fever) allergy. There have been cases of U. chartarum causing skin surface and deep skin infections in immuno-suppressed patients. U. botrytis has no proven pathogenicity.

Alternaria (all-tur-nair’-ee-uh) is another dark-colored mold. Alternaria species are among the most abundant fungi. It’s very closely related to Ulocladium. Alternaria can cause allergic reactions. It’s common in dust, around windows, damp areas, in soil, on foodstuffs, textiles, and on plants.  Exposure to Alternaria can provoke respiratory and asthmatic symptoms in susceptible persons.

If this article was helpful, you may also benefit from reading our list of common household moulds.