Host Range of Rust Isolates on Oregano and Mint in Florida

Fig. 6B. Lower surfaces of the same spearmint leaf (left) and peppermint leaf (right). Inoculated spearmint leaves exhibited chlorosis and abundant uredinial formation, while inoculated peppermint leaves remain uninfected.



Image from Plant Health Progress article:
Host Range of Rust Isolates on Oregano and Mint in Florida