Xerombrophila crystallifera , a new genus and species in the Helotiales
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ORIGINAL ARTICLE
Xerombrophila crystallifera, a new genus and species in the Helotiales Hans-Otto Baral & Guy Marson & Mesfin Bogale & Wendy A. Untereiner
Received: 16 May 2012 / Revised: 21 August 2012 / Accepted: 24 August 2012 # German Mycological Society and Springer 2012
Abstract Xerombrophila, a new member of the Helotiales, is erected for a previously undescribed species that macroscopically resembles genera such as Phaeohelotium or Pezicula. The new species, for which we propose the name X. crystallifera, is characterized by a strong gelatinization of the medullary excipulum as well as the covering layer of the ectal excipulum, by the presence of abundant octahedral crystals, asci with an euamyloid apical ring that resembles the Calycina-type, and paraphyses containing refractive vacuoles. It can also be distinguished from members of both Ombrophila and Phaeohelotium in that it is desiccationtolerant by surviving several weeks in the dry state. The species appears to be confined to xeric bark of Salix and was exclusively found over waterlogged soil, irrespective of being acidic or calcareous. It is known from various planar and colline areas of temperate Europe, and can be found throughout the year. Phylogenetic analysis of partial LSU sequences positions X. crystallifera as a sister taxon of a clade within the Helotiaceae s.l. that includes Ascocoryne, Chloroscypha, Gelatinodiscus, Neobulgaria and "Sarcoleotia" turficola. Keywords Ascomycota . Ombrophila . Phaeohelotium . Phylogeny . Ribosomal DNA sequences
H.-O. Baral (*) Blaihofstr. 42, Tübingen 72074, Germany e-mail: [email protected] G. Marson 45 B, rue de Bettembourg, Hesperange 5810, Luxembourg M. Bogale : W. A. Untereiner Department of Biology, Brandon University, Brandon R7A 6A9, Canada
Introduction In 1988, we (G.M. and H.B.) collected a discomycete growing on the bark of Salix, characterized by its crowded, sessile, gelatinous, yellowish apothecia with a white pruina consisting of abundant octahedral crystals. Although it superficially resembles species of Pezicula Tul. & C. Tul., Phaeohelotium Kanouse, and Rodwayella Spooner, detailed study of this collection showed that it could not be identified with any of these genera. This species is also strongly reminiscent of Ombrophila in its gelatinous consistency and the presence of abundant crystals, but the comparison with members of Ombrophila revealed that it could not be easily accommodated in this genus. A thorough comparison of the descriptions of the members of the Helotiaceae led us to conclude that the species could neither be assigned to a currently recognized genus nor to a described species (Plates 1, 2, 3, 4, 5, 6). We, therefore, describe the new helotialian genus, Xerombrophila, to accommodate this species. We also explored the phylogenetic position of X. crystallifera based on the analyses of nuclear large subunit (LSU) ribosomal RNA gene sequences (Plate 8). During the past few decades, X. crystallifera has been repeatedly recorded at 15 sites so far in central and northern Europe
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