Frances Meehan Latterell (December 21, 1920 – November 5, 2008) was an American plant pathologist whose research in the late 1940s opened a major new area of inquiry into the physiological basis of plant disease.
She was the senior author on a classic 1947 paper showing that the toxin victorin, produced by the pathogenic fungus Helminthosporium victoriae, caused symptoms of Victoria blight of oats, a new disease first described by Latterell and her major professor in 1946.
This discovery of a host-specific toxin, as victorin was later named, gave scores of subsequent researchers new model systems for studying plant disease.