Rogerpetersonia torreyae (Bonar) Aime & McTaggart, comb. nov.

MycoBank number: MB 836608; Index Fungorum number: IF 836608; Facesoffungi number: FoF;

Basionym: Caeoma torreyae Bonar, Mycologia 43: 62. 1951.

Description: Rogerpetersonia torreyae is described and illustrated as C. torreyae in Peterson (1974). Spermogonia are deep-seated, periphysate, otherwise similar to Group III (type 12). Aecia petersonia-like, i.e., without peridium or intercalary cells. Sporothallus unknown.

Notes: Caeoma, as typified by C. berberidis, is a synonym of Puccinia (Aime et al. 2018b), necessitating a new name for the only known rust fungus that infects Torreya. Peterson (1974) hypothesized that R. torreyae belonged to an undescribed early diverging lineage of Pucciniales. Subsequent analyses have shown that R. torreyae is the earliest diverging extant rust sequenced to date and holds an isolated position within Pucciniales (Aime 2006, Aime et al. 2018a) (Fig. 1). No alternate host is known for this rust and it is likely that R. torreyae has adapted to cause systemic infections in the gametothallus host in order to compensate for loss of a sporothallus.