Phytophthora Infestans

Phytophthora infestans is an oomycete, a water mold that despite superficially resembling a fungus is more closely related to algae and diatoms, distinguished in part by cell walls made of cellulose rather than the chitin found in true fungi, and by the production of swimming spores. It causes late blight, a destructive disease of potato and tomato plants that flourishes in cool, moist conditions, and it was responsible for major nineteenth century famines, most notably the Irish Potato Famine of 1845 to 1852. Its scientific name, coined in 1876 by German scientist Heinrich Anton de Bary, combines Greek and Latin roots meaning roughly plant destroyer.