Colonies developing in the hymenium of the host, scarcely visible macroscopically. Mycelium brownish, septate, smooth-walled, not constricted at the septa, ca 1 µm diam.
Conidiophores hardly distinguished from vegetative hyphae, frequently branched, pale brown, smooth-walled, septate, distinctly constricted at the septa, 25-50 µm long and 1.7-3 µm thick. Conidiogenous cells monoblastic, rarely polyblastic, not differentiated from the conidiophore cells, subcylindrical to ellipsoidal, pale brown. Conidia subglobose to ellipsoidal, brownish, aseptate or rarely 1-septate, thin- and smooth-walled, catenate, with chains often branched, composed of 1-20 conidia, 3-4.5 x 2.5-4 µm in size.
Teleomorph: not known.
Description adapted from Diederich (1990).
Distinguished by the mostly aseptate conidia formed in chains. The very simple morphology of Intralichen species makes differentiating between them difficult, and the species concepts are likely to be artificial.
In hymenia and less frequently in the thallus of a broad range of lichen species, including Caloplaca s.l. species, Catillaria chalybeia, C. lenticularis, Lecanora albescens, Lecania erysibe, Porpidia contraponenda, Strangospora moriformis and Trapelia placodioides.
Currently reported from VC3 S Devon, VC9 Dorset, VC19 N Essex, VC25 E Suffolk, VC52 Anglesey, VC89 E Perthshire and VC93 N Aberdeen. Undoubtedly overlooked.