Thelebolus

Thelebolus is a genus of fungi in the Thelebolaceae family. Often considered related to Pezizales, 18S phylogenies show Thelebolales are a sister group to Pseudeurotiaceae and Leotiales. ITS is an adequate DNA barcode but there are only six variable sites in Thelebolus; β-tubulin is a recommended secondary barcode.

Their ascomata are < 500 ųm diam. and are usually considered apothecia. Cleistothecium-like or perithecium-like variants occur, but all have asci arranged in a hymenium. Most species have eight ellipsoidal ascospores in a club-shaped ascus, but some Thelebolus asci have hundreds of ascospores. Ascospores are forcibly ejected synchronously in a sticky mass. Agar colonies are smooth and pinkish, conidium producing collars ("phialides") arising directly on hyphae, and slimy, 1-celled, hyaline conidia that appear yeast-like. Ascoma production is favored by media such as carrot agar.