Abstract
A new graminicolous species of Clavicipitaceae, Balansia brunnans sp. nov., has been found to infect Panicum xalapénse. Staining of living host tissues indicates the presence of intercellular endophytic mycelium. Stromata develop just below the nodes on the culms. Balansia brunnans is comparable to Balansia aristidae, B. discoidea, B. gaduae, B. nigricans, and B. strangulans in development of stromata on culms and possession of an endophytic mycelial stage. Among the differences between Balansia brunnans and other comparable species is that it possesses a brown perithecial stroma, whereas comparable species have black perithecial stromata. A key is provided to distinguish B. brunnans from similar species.