In: Sydowia 74, (2021): 065-070; ISSN 0082-0598, DOI 10.12905/0380.sydowia74-2021-0065, Published online on August 30, 2021

Bacidina celtica (Ramalinaceae), a new lichen species
from western Europe

Pieter P.G. van den Boom & Esteve Llop

Arafura 16, NL-5691JA, Son, The Netherlands
Department of Evolutive Biology, Ecology & Environmental Sciences, Botany & Mycology, Universitat de Barcelona,
Avda. Diagonal 643, 08028 Barcelona, Spain.

e-mails: pvdboom@kpnmail.nl; ellop@ub.edu

van den Boom P.P.G & Llop E. (2021): Bacidina celtica (Ramalinaceae), a new lichen species from western Europe. –
Sydowia
74: 65-70.

Bacidina celtica is described from western Europe, growing terricolous on sandy soil and over bryophytes. It is distinguished
by the coralloid thallus containing goniocysts with polygonal cells, and apothecia fixed to the substratum with colourless hyphae
taking a ± byssoid aspect. This taxon differs from other species in the genus by the ascospores, habitus and habitat.

Keywords: terricolous, muscicolous, biogeography, chorology, taxonomic novelty. – 1 new species.