Micarea cinerea (Schaer.) Hedl.

Bih. K. Svenska Vetensk.-Akad. Handl., 3, 18: 81, 1892. Basionym: Lecidea cinerea Schaer. - Lich. Helv. Spicil., 3: 156, 1828.
Synonyms: Bacidia cinerea (Schaer.) Trevis.; Biatora delicatula Körb.; Bilimbia cinerea (Schaer.) Körb.; Bilimbia delicatula (Körb.) Körb.; Hastifera tenuispora D. Hawksw. & Poelt; Lecidea sphaeroides var. albella Schaer.
Distribution: N - Frl (Tretiach & Hafellner 2000), TAA (Nimis & al. 2015, Brackel 2016), Lomb, Piem, Lig (Giordani & al. 2002).
Description: Thallus crustose, endosubstratic or thinly episubstratic, when well-developed consisting of scattered to contiguous, greenish white to blue-grey, convex to subglobose areoles. Apothecia very rare, micareoid, round, sessile, not constricted at base, up to 0.7 mm across, sometimes confluent into tuberculate, to 1.3 µm wide aggregates, with an ivory white (in shade-forms) or pale to dark grey-black, soon convex disc, and a very thin, soon excluded proper margin. Proper exciple poorly evident, developed only in young apothecia, colourless; epithecium poorly differentiated from the hymenium; hymenium colourless to olive-green or blue-green in upper part, 55-70 μm high, the pigmented parts K- and N+ red; paraphyses conglutinated, branched and anastomosing, 1-1.4 μm thick, the apical cells to 2 μm wide; hypothecium colourless. Asci 8-spored, cylindrical-clavate, the I+ blue tholus with a wide, I+ dark blue tube structure that expands towards the top, without a pale axial body. Ascospores (3-)5-7-septate, hyaline, fusiform-elongate, thin-walled, (19-)23-34(-38) x 4-6 μm. Pycnidia prominent, wart-like, basally immersed in the thallus, paler around the depressed, crater-like ostiolar region, the wall K-. Macroconidia 9-17-septate, flexuous, filiform, 50-110 x c. 1 μm; microconidia narrowly fusiform, to 5 μm long. Photobiont micareoid, thin-walled, the cells 4-7 μm in diam. Spot tests: thallus, apothecial and pycnidial sections K-, C+ red, KC+ red, P- (reactions best visible under the microscope). Chemistry: gyrophoric acid.
Note: a cool-temperate to probably circumboreal-montane species found on the acid bark of deciduous and coniferous trees and on epiphytic bryophytes, in humid montane to subalpine forests, more rarely on lignum of fallen, decorticated trunks and on siliceous pebbles. The Italian distribution seems to be restricted to the Alps.
Growth form: Crustose
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual
Most common in areas with a humid-warm climate (e.g. most of Tyrrenian Italy)

Commonnes-rarity: (info)

Alpine belt: absent
Subalpine belt: rather rare
Oromediterranean belt: absent
Montane belt: 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

Pier Luigi Nimis - CC BY-SA 4.0
TSB 14614

P.L. Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (35213)
widely gaping blackish pycnidia producing macroconidia

P.L. Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (24614)

P.L. Nimis CC BY-SA 4.0
TSB 24614