Geosmithia

About

Geosmithia is a genus of anamorphic fungi of uncertain familial placement in the order Hypocreales. The genus, circumscribed by Australian mycologist John Pitt in 1979, is widely distributed. A 2008 estimate placed ten species in the genus, but several new species have since been described. Thousand cankers disease, which affects economically important black walnut populations in North America, is caused by Geosmithia morbida.

Summary from Wikipedia