The genus Rhizomucor is distinguished from Mucor by the presence of stolons and poorly developed rhizoids at the base of the sporangiophores and by the thermophilic nature of its two species: R. miehei and R. pusillus. Both of these species are potential human and animal pathogens and were originally classified in the genus Mucor. Rhizomucor pusillus is cosmopolitan and both R. miehei and R. pusillus have been reported as pathogens to humans and animals, the latter to a greater extent.
References: Cooney and Emerson (1964), Schipper (1978), Domsch et al. (1980), McGinnis (1980), Ellis and Keane (1981), Scholer et al. (1983), de Hoog et al. (2000, 2015), Schipper and Stalpers (2003) and Ellis (2005b).
Identification of most Mucorales is based primarily on the morphology of the sporangia; i.e. arrangement and number of sporangiospores, shape, colour, presence or absence of columellae and apophyses, as well as the arrangement of the sporangiophores and the presence or absence of rhizoids. Growth temperature tests can also be especially helpful in identifying and differentiating members of the genera Rhizomucor, Rhizopus and Lichtheimia.