Puccinia xanthii

Puccinia xanthii is a fungal pathogen of plants in the Asteraceae, and can infect hosts from at least 42 genera within that family, most notably species in the Xanthium and Ambrosia genera. This pathogen was discovered growing on Xanthium strumarium in North Carolina, United States in 1822. Common names of P. xanthii include Summer Rust and Cocklebur Rust.