Potato Blight Fungus (Phytophthora infestans)

Potato late blight, caused by the fungus Phytophthora infestans, is one of the most important potato diseases in the world. It was responsible for the great Irish Potato Famine of the 1840's, leaving over 1 million people dead from famine-related diseases and resulting in the exodus of more than 1.5 million people from Ireland.