Megalohypha A. Ferrer & Shearer, in Ferrer et al., Mycologia 99: 458 (2007).
Saprobic on host. Sexual morph: Ascomata superficial on wood, globose to obpyriform, ostiolate, papillate, stalked or sessile, connected to the substratum by broad, brown, septate, stoloniferous hyphae. Peridial wall of large, hyaline, thin-walled cells. Hamathecium pseudoparaphysate, pseudoparaphyses septate, branched, anastomosing above the asci. Asci fissitunicate, broadly clavate or fusiform, short pedicellate, 8-spored. Ascospores brown to dark brown, 1-septate, symmetrical, rough-walled, longitudinally striate. Asexual morph: See Notes (Adapted from Ferrer et al. 2007).
Type species: Megalohypha aqua-dulces A. Ferrer & Shearer
Notes: Megalohypha was introduced by Ferrer et al. (2007) with M. aqua-dulces as type species. Megalohypha is characterized by globose to obpyriform, ostiolate, papillate ascomata, hyaline, thin-walled peridial cells, broadly clavate or fusiform, short pedicellate asci and brown to dark brown, 1-septate, symmetrical ascospores. Megalohypha is unique and differs from other genera in Jahnulales in having vegetative hyphae and ascomatal stalks that are deeply constricted at the septa (Ferrer et al. 2007). Megalohypha has ascospores which have bipolar symmetry, acute to rounded apices, a dark band at the midseptum and sulcate striations on the ascospore wall. Megalohypha also differs from Jahnula in that the latter has more mature ascomata which are strongly pigmented brown and have thicker peridium compared to those of Megalohypha. Megalohypha resembles Aliquandostipite in ascospores morphology but differs in that the ascospores of Aliquandostipite are more elongated, hyaline to pale brown, the upper cell is larger than the lower cell and enclosed in a large gelatinous sheath (Inderbitzin et al. 2001; Raja et al. 2005) and lack wall striations. Megalohypha is morphologically and phylogenetically a monotypic distinct genus in Aliquandostipitaceae. Molecular markers available for Megalohypha include LSU and SSU.