Lecanora phaeostigma (Körb.) Almb.

in Santesson, The Lichens of Sweden and Norway: 148, 1984. Basionym: Biatora phaeostigma Körb. - Syst. Lich. Germ.: 199, 1855.
Synonyms: Biatora obscurella (Sommerf.) Arnold; Lecanora obscurella (Sommerf.) Hedl.; Lecidea obscurella (Sommerf.) Nyl.
Distribution: N- Ven. S - Cal (Puntillo 1996, Puntillo 2011).
Description: Thallus crustose, episubstratic or rarely indosubstratic, continuous to granular-verrucose, sometimes reduced to sparse, flat areoles surrounding the apothecia, ochre-coloured to brown or greenish brown. Areoles usually scattered, thin, ecorticate, smooth, somehow shiny. Apothecia clearly (pseudo-)lecanorine only when young, later appearing biatorine, abundant and often crowded, sessile, 0.2-0.7 mm across, with a reddish brown to dark brown, flat to finally strongly convex to hemispherical disc, and a paler, thin, entire, finally excluded thalline margin. Thalline exciple with very few algal cells, evident only in young apothecia; proper exciple thin, brown in outer part, colourless within; epithecium brown, the pigment dissolving in K, N-, K- or K+ greenish or olive-brown, without crystals; hymenium colourless, not inspersed with oil droplets; paraphyses capitate; hypothecium colourless, not inspersed with oil droplets. Asci 8-spored, clavate, with a homogeneously I+ blue tholus, without an amyloid axial mass, Catillaria- or Fuscidea-type. Ascospores 1-celled, hyaline or sometimes pale brown when overmature, narrowly ellipsoid, 8-12 x 3-5 μm, the wall <1 µm thick. Pycnidia usually abundant, immersed, black. Conidia cylindrical to ellipsoid, 3-4 x 1.5-2 µm. Spot tests: thallus K-, C-, KC-, P-. Chemistry: 2-methylene-3-carboxy-18-hydroxynonadecanoic acid.
Note: this species, which is related to L. cadubriae, seems to be widespread in northern and central Europe; it grows on the bark of conifers, especially near the base of the trunks, more rarely on lignum of decorticated trunks, with optimum in the upper montane and subalpine belts; probably more widespread in the Alps.
Growth form: Crustose
Substrata: bark
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual

Commonnes-rarity: (info)

Alpine belt: absent
Subalpine belt: very rare
Oromediterranean belt: absent
Montane belt: very rare
Submediterranean belt: absent
Padanian area: absent
Humid submediterranean belt: absent
Humid mediterranean belt: absent
Dry mediterranean belt: absent

pH of the substrata:


Solar irradiation:








Altitudinal distribution:


Predictive model
Herbarium samples

P.L. Nimis CC BY-SA 4.0
TSB 8206

P.L. Nimis CC BY-SA 4.0
TSB 8206