Colonies are rapid growing, brown to olivaceous-black or greyish and suede-like to floccose. Microscopically, solitary, darkly pigmented, terminal, multicellular conidia (dictyoconidia) are formed on a distinctive conidiophore with a darker terminal swelling. Note the conidiophore proliferates percurrently through the scar where the terminal conidium (poroconidium) was formed. Conidia are pale to mid-brown, oblong, rounded at the ends, ellipsoidal, obclavate or subspherical and are smooth or in part verrucose. Stemphylium should not be confused with Ulocladium which produces similar dictyoconidia from a sympodial conidiophore, not from a percurrent conidiogenous cell as in Stemphylium.
Conidiophores and conidia of Stemphylium sp.
Most species are plant pathogens with occasional isolates from soil, they are rarely seen in the clinical laboratory.
Rippon, J.W. 1988. Medical Mycology. 3rd Edition. W.B. Saunders Co., Philadelphia, USA.
McGinnis, M.R. 1980. Laboratory handbook of medical mycology. Academic Press, London, UK.