Unraveling two East Asian species of Clinoconidium (Cryptobasidiaceae)

The obscure species Exobasidium sawadae and the enigmatic hyphomycetous genus Elaeodema transform fruits of Cinnamomum species to galls. Fresh collections from Guangxi in China and Taiwan island were studied with microscopy and analysis of partial large subunit (LSU) ribosomal RNA gene sequences. Study of young stages and of isotype material of El. cinnamomi revealed the presence of basidia. Haustoria are demonstrated in both species for the first time. Sterile elements were found between basidia in galls of El. cinnamomi, whereas sterile elements were absent in Ex. sawadae. Based on the morphology of spore germination and the anamorphic yeast stage in culture, and a phylogenetic species concept, these two species were combined into Clinoconidium. Elaeodema is considered a synonym of Clinoconidium. The data indicate high specificity of Clinoconidium species to their lauraceous hosts.