Hypoxylon anthochroum, H. polyporum, Xylaria microceras, X. pallide-ostiola
ta, and X. uniapiculata are reported for the first time from the Mexican st
ate of Sonora. Descriptions of Xylaria microceras and X. uniapiculata are e
nhanced by the communication of their cultural and anamorphic data. An arti
ficial key to the known Sonoran Xylariaceae is provided.