Lignicolous freshwater ascomycota from Thailand: Micropeltopsis quinquecladiopsis sp nov.

A new freshwater ascomycete Micropeltopsis quinquecladiopsis sp. nov, was c ollected on submerged twigs in a stream in Thailand. The fungus is describe d at the light microscope, scanning and transmission electron microscope le ver. Distinctive features are the appendaged 1-septate hyaline ascospores. The appendage arises as an outgrowth of the episporium from a basal stalk, then divides into five arms (three long and two short). The episporium and appendages are surrounded by an indistinct (at light microscope level) muci laginous layer. The fungus is assigned to the Dothideales (Trichothyriaceae ). Ascospore appendage ontogeny is compared with those of,marine Ascomycota (Halosphaeriales).