Rhizopus stolonifer

This fungus has a worldwide distribution, occurring most densely in soils of warm climates. R. stolonifer is one of the most frequently observed indoor air fungi and commonly grows on foods (e.g. bread) and its spores can germinate on moist paper. It appears that growth is enhanced by slightly alkaline conditions. This species has caused occasional infections, but it is not generally regarded as an important pathogen.