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
Botryostroma Höhn., Sber. Akad. Wiss. Wien, Math.-naturw. Kl., Abt. 1 120: 424 (1911)
Saprobic on leaves of unidentified host. Sexual morph: Undetermined. Asexual morph: Conidiomata pycnidial, small, very dense or compact, rounded, circular or irregular, black, verrucose, growing from a subcuticular hypostroma, forming a thin single-celled, pseudoparenchymatous, translucent olive-brown crust, depressed in the dried state, papillate. Conidiomata wall outer layer thick, 7–8 layered, composed of thick-walled dark brown to black cells of textura globulosa, innermost wall thin, 2–3 layered of textura angularis, becoming hyaline. Conidiophores reduced to conidiogenous cells. Conidiogenous cells cylindrical or slightly irregular, short, sparsely branched, mostly at the base, hyaline or very pale brown, septate, smooth. Conidia straight, curved or irregular, truncate at the base, obtuse at apex, hyaline or pale brown, multi-septate, usually thin and smooth-walled or verruculose.
Type species – Botryostroma inaequale (G. Winter) Höhn.
Notes – The genus Botryostroma was introduced by Höhnel (1911). The genus is characterised by black ascomata produced under a clypeus, with numerous persistent pseudoparaphyses among asci. The genus was accommodated in Venturiaceae by Muller & von Arx (1962) based on its obclavate or fusiform asci, lightly pigmented, apiosporous ascospores. The asexual morph is coelomycetous. Due to its uncertain taxonomic placement, Botryostroma was accepted as a genus in Dothideomycetes, genera incertae sedis (Kirk et al. 2013, Wijayawardene et al. 2017). Currently, two species are accommodated in the genus. Cultures and sequences are unavailable. We re-studied the holotype specimen of Botryostroma inaequale under the basionym Lizonia inaequalis G. Winter with the code F10863 from S herbarium. We did not observe any sexual characters in the specimen. Based on the asexual morphological characters, we are uncertain regarding the taxonomic placement of the genus, hence we retain Botryostroma in Dothideomycetes, genera incertae sedis.