Bacidina Pycnidiata

''Bacidina'' is a genus of crustose lichens in the family Ramalinaceae.

Taxonomy

The genus was circumscribed by Czech lichenologist Antonín Vězda in 1990, with ''Bacidina phacodes'' assigned as the type species. Vězda included 11 species in ''Bacidina'', which was originally classified in the Lecideaceae. These species had previously been placed in genus ''Bacidia''.

Description

''Bacidina'' species are crustose lichens, forming thin, often inconspicuous thalli that may be smooth, cracked, warted, or . Some species develop specialised reproductive structures such as soredia, isidia, or microsquamules. The thallus is typically pale in colouration, ranging from whitish and pale green to greyish or fawn. The photosynthetic partner () consists of algae, which have roughly spherical () to broadly ellipsoidal cells.

The reproductive structures, or apothecia, are relatively small, usually up to 1 mm in diameter, and can be flat or strongly convex. They lack a distinct but have a well-developed , which is composed largely of thick-walled cells with isodiametric to ellipsoidal . This distinguishes ''Bacidina'' from ''Bacidia'', which has a true exciple made of radiating hyphal tissue with narrow lumina. The hymenium, a spore-producing layer, reacts with iodine (I+) to stain blue. The underlying varies in colouration from colourless to pigmented. The paraphyses within the hymenium are generally few in number, sometimes branched, and often have swollen tips.

The asci, which produce the , are club-shaped () to cylindrical-clavate in shape and typically contain eight spores. Most ''Bacidina'' species have asci of the ''Bacidia'' type, characterised by an apical dome that stains dark blue in K/I with a pale, conical apical cushion. In some species, the ascus resembles the ''Biatora'' type, which has a darker-staining zone around the apical cushion. The ascospores are colourless, generally three- or more-septate at maturity, and often (thread-like), (needle-shaped), or sigmoid (curved like an "S"), though some species have spores that are cylindrical to fusiform. A distinct outer spore coating () is absent.

Asexual reproduction occurs through conidia, which are produced in small, often or sessile pycnidia. The conidia are colourless and vary in shape, with some species producing septate conidia. ''Bacidina'' species do not contain secondary metabolites that react with common chemical spot tests (C–, K–, KC–, Pd–, I–, UV–), but their apothecia and pycnidia may contain a variety of pigments.

Species

, Species Fungorum (in the Catalogue of Life) accepts 53 species of Bacidina, although a total of 85 taxa have been described in the genus.

*'' Bacidina acerina'' – Europe
*'' Bacidina adastra''
*'' Bacidina aenea''
*'' Bacidina aeruginosa''
*'' Bacidina apiahica''
*'' Bacidina arnoldiana''
*'' Bacidina arvidssonii''
*'' Bacidina assulata''
*''Bacidina brandii''
*'' Bacidina brittoniana''
*'' Bacidina caerulea''
*'' Bacidina californica''
*'' Bacidina caligans''
*'' Bacidina canariensis''
*'' Bacidina celtica''
*'' Bacidina chloroticula''
*'' Bacidina cinnamomea''
*'' Bacidina circumpallens''
*'' Bacidina circumpulla''
*'' Bacidina clauzadei''
*'' Bacidina contecta''
*'' Bacidina convexa'' – Panama
*'' Bacidina crystallifera''
*'' Bacidina defecta''
*'' Bacidina delicata''
*'' Bacidina dichroma'' – Guatemala
*'' Bacidina digitalis''
*'' Bacidina dissecta''
*'' Bacidina egenula''
*'' Bacidina etayana''
*'' Bacidina ferax''
*'' Bacidina flavoleprosa''
*'' Bacidina fuscosquamulosa'' – Guatemala
*'' Bacidina hypophylla'' – Brazil
*''Bacidina indigens''
*'' Bacidina inundata''
*'' Bacidina iqbalii'' – Pakistan
*'' Bacidina jasonhurii''
*'' Bacidina lacerata''
*'' Bacidina lignicola''
*'' Bacidina loekoesiana''
*'' Bacidina maculans''
*'' Bacidina margallensis'' – Pakistan
*'' Bacidina medialis''
*'' Bacidina mendax'' – Europe
*'' Bacidina mirabilis''
*'' Bacidina modesta''
*'' Bacidina multiseptata''
*'' Bacidina neglecta''
*'' Bacidina neosquamulosa''
*'' Bacidina neotropica''
*'' Bacidina pallidocarnea''
*'' Bacidina pallidocarpa'' – Macaronesia
*'' Bacidina paradoxa''
*''Bacidina phacodes''
*'' Bacidina piceae''
*'' Bacidina populnea''
*'' Bacidina pseudohyphophorifera''
*'' Bacidina pseudoisidiata'' – Tenerife
*'' Bacidina pulverula'' – Ecuador
*'' Bacidina pycnidiata''
*'' Bacidina saxenii''
*'' Bacidina scutellifera''
*'' Bacidina simplex''
*'' Bacidina squamellosa''
*'' Bacidina sorediata''
*'' Bacidina streimannii''
*'' Bacidina subfuscula''
*'' Bacidina sulphurella''
*'' Bacidina tarandina''
*'' Bacidina tenella''
*'' Bacidina terricola''
*'' Bacidina varia''
*'' Bacidina vasakii''
*'' Bacidina violacea'' – Macaronesia
*'' Bacidina ziamensis''

References

{{Taxonbar, from=Q4838938

Lichen genera
Lecanorales genera
Taxa described in 1991
Taxa named by Antonín Vězda