Citation: Pem D et al. (2019) Mycosphere Notes 275-324: A morphotaxonomic revision and typification of obscure Dothideomycetes genera (incertae sedis). Mycosphere 10(1), 1115–1246
Hassea Zahlbr., Beih. Botan. Centralbl. 13: 150 (1902)
Lichenicolous on the rock. Sexual morph: Ascomata perithecial, subglobose to applanate, carbonaceous, black, smooth or rough, semi-immersed or superficial in the thallus of the host, ostiolate, with a central ostiole located in a papilla; singly scattered or more rarely crowded in small groups, slightly glistening. Peridium continuous, composed of three layers: an inner excipular layer and two outer involucrellum layers; extemal involucrellum layer is carbonaceous, consisting of isodiametric, thick-walled cells, with enlarged lumina and black walls; intemal involucrellum layer is colorless to black, paraplectenchymatous, consisting of isodiametric, thin-walled cells, with enlarged lumina and a colorless to pigmented wall; intemal involucrellum layer is thicker than the extemal one; excipular layer: thinner, hyaline, composed of cells becoming laterally compressed, with thin, colorless walls and enlarged lumina. Hamathecium composed of paraphyses and periphyses. Paraphyses septate, simple and poorly branched becoming evanescent, branched, hymenial gelatineous. Asci elongate claviform to cylindrical, shortly stalked, unitunicate, thin-walled, slightly thickened at the apex of young asci, 8-spored. Ascospores overlapping in the ascus, simple, cylindrical to filiform, one or more transverse septa, not constricted at the septa, thin-walled without mucilaginous sheath. Asexual morph: Undetermined.
Type species – Hassea bacillosa (Nyl.) Zahlbr.
Notes – Hassea was introduced by Zahlbruckner (1902) to accommodate the type species H. bacillosa (Nyl.) Zahlbr. and is characterised by perithecial ascomata, elongate claviform to cylindrical unitunicate asci and hyaline, cylindrical-bacilliform ascospores. Hassea was included as a genus in Dothideomycetes genera incertae sedis (Lumbsch & Huhndorf 2010, Kirk et al. 2013, Wijayawardene et al. 2018). The asexual morph is unknown. Cultures and sequences are unavailable for the type species. We re-examined the type specimen Hassea bacillosa from FH under the code FH 00213640. Based on its morphology Hassea could not be accommodated in any of the family in the class Dothideomycetes. We therefore, transfer the genus Hassea to Sordariomycetes genera incertae sedis based on its claviform to cylindrical unitunicate asci.