RESUMEN
Knowledge of sequestrate Hysterangiaceae fungi in Mexico is very limited. In the present study, a new member of the family, Aroramyces guanajuatensis sp. nov., is described. This speciesis closely related to A. balanosporus, but differs from the latter in possessing a tomentose peridium 165-240 µm thick, with occasional large terminal hyphae up to 170 µm, a variable mesocutis (isodiametric to angular), and distinct bright yellowish subcutis. In contrast, A. balanosporus possesses a fibrillose peridial surface with shorter hyphae, a peridium 200-450 µm thick, and a mainly hyaline isodiametric mesocutis with a slightly wider subcutis. The phylogenetic analysis of the LSU gene separated A. guanajuatensis from A. balanosporus with a Bayesian posterior probability (PP) = 1. This is the third Aroramyces species described for the American continent.