First Report of Hypoxylon diatrypeoides Inducing Dieback and Black Trunk Rot on Mesquite (Prosopis laevigata) in Mexico.

During 2001, branch dieback, black trunk rot, and resinosis were observed on mesquite in the biosphere reserve of Tehuacan, Mexico (18°15'N, 97°25'W) A light brown growth, which included Nodulosporium-like conidiosphores and hyaline conidia that were green in mass and ellipsoid with one end truncate developed on diseased branches. Below the conidiophores and conidia, glomerate to pulvinate stromata formed with conspicuous, black, perithecial mounds with globose perithecia. Ascospores were dark brown, unicellular, ellipsoid, nonequilateral, with narrowly rounded ends, a straight germ slit with a perispore that was dehiscent in 10% KOH, and a conspicuous coil-like, smooth epispore.