Hydropisphaera

Hydropisphaera is a genus of perithecial ascomycetes characterized by their specific ascomatal wall structure and rapid collapse upon drying. They are often found on decaying herbaceous stems and wood. The genus was resurrected and redefined by Rossman et al. (1999) to accommodate species formerly placed in Nectria that possess specific wall traits and Acremonium-like anamorphs.