phy·ma·tot·ri·chum \ˌfīməˈtä.trə̇kəm\noun Etymology: New Latin, from phymato- (from Latin phymat-, phyma) + -trichum (from Greek trich-, thrix hair) — more at trichina 1.capitalized: a genus of imperfect fungi (order Moniliales) including a species (P. omnivorum) that causes cotton root rot and similar rots of various other plants 2.-s: any fungus of the genus Phymatotrichum