Calicium montanum Tibell
Mycotaxon, 70: 432, 1999.
Synonyms:
Distribution: C - Tosc (Tibell 1999, Puntillo & Puntillo 2009).
Description: Thallus crustose, episubstratic, granular to verrucose, pale grey to grey-green. Apothecia stalked, pin-like, 0.3-0.4 mm high, black, white-pruinose on the outer surface of the capitulum. Stalk black, epruinose, 0.11-0.2 mm thick, of dark brown, irregularly interwoven and strongly sclerotized hyphae, the outermost layer gelatinous, hyaline; capitulum obovoid to lenticular, 0.2-0.3 mm across, with a dark brown to aeruginose-green exciple of almost isodiametric, sclerotized cells; hypothecium dark brown, flat to slightly convex. Asci cylindrical-clavate, formed singly, dissolving early, with uniseriately arranged spores. Ascospores 1-septate, brown, ellipsoid, 9-11.5 x 5-6 µm, with coarse, irregular cracks. Photobiont chlorococcoid. Spot tests: thallus K-, C-, KC-, P-. Chemistry: divaricatic and 2-O-methyldivaricatic acids.Note: a recently-described, rare but widespread species with a relatively thick, pale grey thallus, short-stalked apothecia with white pruina, and ascospores with coarse irregular cracks, found on lignum, especially on decorticated stumps of Castanea, but also on conifers in the Alps; perhaps more common in Italy. The species is included in the Italian red list of epiphytic lichens as “Critically Endangered” (Nascimbene & al. 2013c).
Growth form: Crustose
Substrata: lignum
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual
In underhangs rarely wetted by rain
Commonnes-rarity: (info)
Alpine belt: absent
Subalpine belt: absent
Oromediterranean belt: absent
Montane belt: very rare
Submediterranean belt: absent
Padanian area: absent
Humid submediterranean belt: very rare
Humid mediterranean belt: absent
Dry mediterranean belt: absent

Predictive model
Growth form: Crustose
Substrata: lignum
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual
In underhangs rarely wetted by rain
Commonnes-rarity: (info)
Alpine belt: absent
Subalpine belt: absent
Oromediterranean belt: absent
Montane belt: very rare
Submediterranean belt: absent
Padanian area: absent
Humid submediterranean belt: very rare
Humid mediterranean belt: absent
Dry mediterranean belt: absent

Predictive model