Histoplasma capsulatum is a true pathogenic, thermal dimorphic fungus, existing in the form of mycelia at 25˚C and in the form of yeast at 37˚C (body temperature). Histoplasma capsulatum var. capsulatum causes the disease most commonly labeled Histoplasmosis mentioned below. Its teleomorph name is Ajellomyces capsulatus,⁸, although the teleomorph is seldom seen.

<img src=“http://botit.botany.wisc.edu/...; align=right alt=“Histoplasma capsulatum at 25 C and 37 C”>

Histoplasma capsulatum at http://botit.botany.wisc.edu/toms_fungi/jan2000.html