By Baral H.-O.
Vol. 14 (2) – 25 April 2022
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Abstract: Three species growing on monocotyledonous hosts in semiaquatic habitats are accepted within the predominantly lignicolous genus Ombrophila: O. pileata, O. costantinii, and O. ambigua. This result is based on the personal reexamination of the type specimens of O. ambigua, O. aquosa, O. pileata, O. longispora, and O. lacustris, and various non-type collections. Together with the illustrated protologues of O. costantinii, O. helotioides, and Leotiella caricicola, the following synonymy could be established: O. longispora, O. lacustris, and O. helotioides are certain, probable, or possible synonyms of O. pileata, respectively, Leotiella caricicola is a synonym of O. costantinii, and O. aquosa is a possible synonym of O. ambigua. The examined type collection of O. pileata turned out to be a mixture comprising also O. costantinii. Problems regarding species delimitation based on morphological variation are discussed. Two collections on dicotyledonous herbs, treated here as O. aff. ambigua, could represent a species of its own. The correlation between ascospore shape (elongated vs. broadly ellipsoid) and inhabited substrate (herbaceous vs. woody) suggests that the three accepted herbicolous species form a natural group, for which the genus Leotiella, previously synonymised with Cudonia, is reduced to a subgenus of Ombrophila. Ombrophila costantinii is proposed as a new combination based on Helotium costantinii.
The genus Ombrophila Fr. (= Neobulgaria Petr.) is characterised by a medullary excipulum of narrow, interwoven hyphae immersed in abundant mucilage (“textura intricata imbuta” fide Hengstmengel, 2020), an ectal excipulum of thin-walled prismatic to isodiametric cells with hardly noticeable mucilage […]