Mouldy pumpkin. Close-up of mould (Rhizopus sp.) growing on a slice of pumpkin. The picture shows many sporangia (black dots) at different stages of development. Each one is borne on the erect stem of the sporangiophore. The sporangia are initially white, but turn grey and black as they mature. Eventually each one will release thousands of asexual spores into the air.