Notes on (Ascomycota, Leotiomycetes), with new species and combinations.

Studies of (Leotiomycetes, Helotiales, Cenangiaceae) are scarce. Here, we describe two new species based on molecular phylogenetic data and morphology. was collected at the Boston Harbor Islands National Recreation Area, Massachusetts. It was found on the stem of , representing the first report of any species from a plant host in the family Apocynaceae. is associated with the uredinia of the rust fungus . It was discovered during a survey for rust hyperparasites conducted at the Arthur Fungarium, in a single sample from 1912 collected in Trinidad. Macro- and micromorphological descriptions, illustrations, and molecular phylogenetic analyses are presented. The two new species are placed in with high support in both our six-locus (SSU, ITS, LSU, , , ) and two-locus (ITS, LSU) phylogenetic reconstructions. In addition, two species are combined in : (formerly placed in ) and (originally described as the only species in ). This study reveals new host plant families, a new ecological strategy, and a new country record for the genus . Finally, our work emphasizes the importance of specimens deposited in biological collections such as fungaria.