Par Lechat C., Fournier J.
Vol. 13 (5) – 29 septembre 2021
Résumé (anglais) : Cosmospora xylariae is described as new to science and illustrated based on six collections from Europe occurring on stromata of Xylaria hypoxylon, X. longipes and X. polymorpha. The placement of this fungus in the genus Cosmospora and its status as a distinct species are based on the study of its sexual and asexual morphs, colour of colony in culture and phylogenetic comparison of ITS1-5.8S-ITS2 sequences with those of cosmospora-like fungi having an acremonium-like asexual morph. Field observations in French Guiana are reported showing the presence of the closely related C. scruposae on dead stromata of X. schweinitzii. C. scruposae is closely related to C. xylariae and was so far considered to be affiliated with X. scruposa only. The status of C. berkeleyana as a distinct species is questioned by the phylogenetic analysis of numerous ITS sequences published under this name in GenBank, one of them being close to C. xylariae. It is determined that Verticillium berkeleyanum, thus C. berkeleyana, is a synonym of Sphaerostilbella berkeleyana. A dichotomous key to species of Cosmospora is presented based on morphological features of sexual state and host affiliation.
In the continuation of our survey of hypocrealean fungi in temperate areas, whose references are compiled in Lechat & Fournier (2021), a species of Cosmospora Rabenh. was repeatedly collected on dead stromata of Xylaria hypoxylon (L.) Grev. and X. polymorpha (Pers.) Grev. in France incubated in a moist chamber, and once in nature on a dead stroma of X. longipes Nitschke in Germany […]