DESCRIPTIONS OF MEDICAL FUNGI

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Descriptions of Medical Fungi
Most species of Stemphylium are plant pathogens with occasional isolates from soil,
they are rarely seen in the clinical laboratory.
RG-1 organism.
Stemphylium Wallroth
Morphological Description: 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.
Molecular Identification: ITS sequencing (Woudenberg et al. 2013).
Key Features: Dematiaceous hyphomycete producing darkly pigmented, dictyoconidia
from the swollen end of a percurrent conidiophore.
References: Ellis (1971, 1976), Rippon (1988), de Hoog et al. (2000).
20 µm
Stemphylium spp. conidiophores and conidia.