An endophyte of (esparto or needle grass) from Tunisia is a novel species in the species complex.

Here, we report on the morphological, molecular, and chemical characterization of a novel species recovered from the roots and rhizosphere of (halfa, esparto, or needle grass) in central Tunisia. Formally described here as , this species is a member of the species complex but differs from the other two species within the complex, and , by its endophytic association with and its genealogical exclusivity based on multilocus phylogenetic analyses. To assess their sexual reproductive mode, a polymerase chain reaction (PCR) assay was designed and used to screen the three strains of , 51 of , and 14 of for mating type () idiomorph. Genetic architecture of the locus in the former two species suggests that if they reproduce sexually, it is via obligate outcrossing. By comparison, results of the PCR assay indicated that 13/14 of the strains possessed and idiomorphs and thus might be self-fertile or homothallic. However, when the strains were selfed, 11 failed to produce perithecia and one only produced several small abortive perithecia. Cirrhi with ascospores, however, were only produced by 8/28 and 4/84 of the variable size perithecia, respectively, of NRRL 29888 and 29890. The potential for the three clade species to produce mycotoxins, pigments, and phytohormones was assessed by screening whole genome sequence data and by analyzing extracts on cracked maize kernel cultures via liquid chromatography-mass spectrometry.