Checklist of Rust Fungi (Basidiomycota, Pucciniales) and their hosts in Indiana, United States of America.

Rust fungi (Pucciniales) comprise a large group of ecologically and economically important plant pathogens distributed globally where their hosts grow. The first published study of rusts in Indiana was carried out 131 years ago, and a revised checklist of all Pucciniales for Indiana has not been compiled since the works of Jackson from 1917 to 1920. Efforts to compile a checklist five years ago revealed a dire need for revision due to taxonomic and nomenclatural changes. We examined historical records, including online databases and literature, as well as new and historical collections in the Arthur Fungarium (PUR) at Purdue University. We provide an annotated checklist of all known species of rust fungi occurring in 90/92 Indiana counties. Names in prior records have been updated to reflect the current classifications for this group, with cross-reference to older names. A total of 301 Pucciniales taxa across 32 genera and their host species have been verified. This work serves as a resource for statewide plant disease diagnosticians and records the extant rust fungal biodiversity in Indiana to guide research efforts, resource management, and conservation.