Lasiothelebolus, A New Genus of the Thelebolaceae (Pezizales)

Abstract

SUMMARY Lasiothelebolus represents a new coprophilous genus of the Thelebolaceae (Pezizales, Ascomycetes). The only species thus far discovered, L. oblongisporus, is described and illustrated. The genus is distinguished from others of the family by its minute citron-yellow apothecia, pigmented paraphyses, and short, blunt, septate hairs of the ectal excipulum. The collection was found on deer dung near Saranac Lake, New York. During our examination of some coprophilous Ascomycetes, a minute bright yellow discomycete having asci that were neither operculate nor inoperculate was encountered and critically studied. Liberation of ascospores conformed to the pattern described for Thelebolus (Kimbrough, 1966) whereby thick-walled ascospores were ejected through an irregular tear created in the thinner-walled ascus apex. Asci (when immature) were thick walled and each displayed, when mounted in 0.5% in 2% KOH, a distinct ring near the apex. However, the presence of seemingly high concentrations of carotinoidlike pigments in the excipulum and in the paraphyses, and the numerous short blunt septate hairs on the excipulum represent features unobserved in Thelebolus. The hairs of L. oblongisporus are characteristically different from any described among the genera of Thelebolaceae. A new genus is proposed to accomodate this unusual discomycete. Lasiothelebolus Kimbr. & Luck-Allen, gen. nov. Apothecia superficialia discoidea pigmentis carotinoideis colorata. Excipulum e cellulis angularibus (textura angulari), non cyanophilis, non dextrinoideis, compositum; ectale excipulum pilis numerosis brevibus septatis tectum; pili imi inflati. Asci muris duobus praediti, quorum externus Congo Red aequabiliter