Naetrocymbaceae Tomasellia gelatinosa Growth type crustose Chemical results negative. Photobiont absent but chlorococcoid algae on bark surface Occurs on the trunks and branches of various trees and shrubs but most frequent on Corylus The thallus is inconspicuous but bleaches the bark, with brown or blackish, +/- round ascomata containing up to 12 perithecia-like locules. Asci are 8-spored, spores (1-)3 septate, 20-28 x (5-)7-8(-10) µm, hyaline then darker with age. Pycnidia with colourless, bacilliform conidia. Micrographs below Similar: Tomasellia diffusa occurs on Alnus, spores brown, 1-septate

Micrographs





Tomasellia gelatinosa
Photographs: Corfe Mullen, Dorset. March 2025