Mucor and Rhizopus are fungi.Mucor is commonly called pin mould, is saprophytic fungus. It grows on stale moist bread, rotten fruits, decaying vegetables, animal dung etc. Rhizopus is known as black mould.
Morphological differences between the two, however, are as follows. Rhizopus consists of a clusters of much branched absorptive hyphae growning downwards in the food medium, groups of aerial hyphae growing upwards from the same node and bearing sporangia, swollen nodes and curved hyphae growing outwards over the surface of the substratum and bearing rhizoids and sporangiophores from the same node in the opposite directions at frequent intervals. Mucor is lacking in rhizoids and stolons, and in it the sporangiophores grow singly and directly on the mycelia.