The agent responsible for the blight that caused the nineteenth-century Irish potato famine, Phytophthora infestans, should not be “grouped with fungi” (Nature 493, 154–156; 2013).

It was Anton de Bary, the father of mycology, who coined the genus name Phytophthora ('plant-destroyer') and classed the pathogen as a fungus. But modern molecular sequencing indicates that his interpretation was incorrect (M. D. M. Jones et al. Nature 474, 200–203; 2011).

The organism is actually an oomycete, a pseudo-fungus that evolved from killer ancestors in the ancient oceans and not from wood-degrading fungi.