Rhizopus

Rhizopus is a common saprobe in the Mucoromycota that grows on a variety of substrates, especially spoiled food. Rhizopus is commonly isolated during culture-based air sampling. In culture Rhizopus produces abundant sporangia at the end of a sporangiophore. As many as 10,000 spores (sporangiospores) develop within each sporangium. The spores are seldom reported from spore trap samples. The spores are allergenic, and there have been reports of this genus as a human pathogen. 

The images below are from a Rhizopus culture and show a black sporangium on a sporangiophore at low magnification on the left and a group of spores (high magnification) on the right.