Oomycetes are a group of superficially fungus-like organisms responsible for some of the most devastating plant diseases. Oomycete plant diseases effect many major crop species, including potato (Phytophthora infestans), legumes (Aphanomyces euteiches), and grape (Plasmopara viticola). Certain species also cause severe disease and destruction in natural ecosystems, including Kauri dieback (Phytophthora agathidicida).