Par Fournier J.
Vol. 6 (3) – 01 juillet 2014
Résumé (anglais) : In the course of an extensive survey of Xylariaceae in the French Central Pyrenees over the last fifteen years two undescribed species of Hypoxylon were recently discovered, both on Fagus sylvatica. Based on the combination of remarkable ecological and morphological characters that does not match known taxa, both species are recognized as new to science. Hypoxylon cazenavei is distinctive in having brown vinaceous effused-pulvinate stromata turning fuscous, with tubular to lanceolate perithecia and yellow brown KOH-extractable pigments. Hypoxylon invadens is diagnosed on its occurrence on aborted primordia of H. fragiforme, its fulvous stromata soon turning shiny black with strongly exposed perithecial contours, slightly carbonaceous subsurface and yellow brown KOH-extractable pigments