Includes most pathogenic fungi. A mass of hyphae is called mycelia. Yeasts are unicellular organisms and mycelia are multicellular filamentous structures, constituted by tubular cells with cell walls. The yeasts reproduce by budding. The mycelial forms branch and the pattern of branching is an aid to the morphological identification.
Some fungi occur in both the yeast and mycelial forms.
These are called dimorphic fungi. This is the form usually seen in tissue, in exudates, or if cultured in an incubator at 37 degrees C. 2. The form observed in nature or when cultured at 25 degrees C. Conversion to the yeast form appears to be essential for pathogenicity. In the dimorphic fungi. Fungi are identified by several morphological or biochemical characteristics, including the appearance of their fruiting bodies.