Abstract
Ascothailandia grenadoidia gen. et sp. nov. is described and illustrated from submerged wood (Wrightia tomentosa) in a stream at Hala Bala Wildlife Sanctuary, southern Thailand. The new genus (teleomorph) is characterized by perithecoid, globose, dark brown, ostiolate ascomata, paraphysate, asci cylindrical, unitunicate with a prominent J-refractive apical ring and versicolurus, 3-euseptate ascospores. Ascospores germinated producing a Canalisporium (C. grenadoidia sp. nov.) anamorph. The morphological characterization of this new fungus is reported and compared with the genera Ascotaiwania and Savoryella. Phylogenetic analyses of the combined partial 18S, 28S ribosomal DNA and internal transcribed spacer, including 5.8S regions, of Ascothailandia grenadoidia and 10 Canalisporium species were undertaken and analyzed with maximum parsimony and Bayesian methods. The molecular data indicate that A. grenadoidia is closely related to Canalisporium elegans in the Sordariomycetes, Hypocreomycetidae, order incertae sedis. Both morphological and molecular characterization provides sufficient evidence to support the description of a new genus. A key to Canalisporium species is provided.