What is the scientific name for penicillin fungus?

Penicillium (from Latin penicillus: paintbrush) is a genus of ascomycetous fungi. The fungi produces penicillin which is a molecule used as an antibiotic.

Penicillium was discovered in 1928 by Alexander Fleming's lab assistant when he left a window open overnight and had mold spores over his bacterial specimens in a petri dish. He nearly threw it away but when he examined it under a microscope he discovered that many bacteria in the petri dish were dying due to the fungi growing around them.