Buellia arnoldii Servít

in Servít & Nádvornik, Vestn. Král. Ceské Spolec. Nauk, 12: 39, 1937.
Synonyms: Hafellia arnoldii (Servít) Hafellner & Türk
Distribution: N - TAA (Nascimbene & al. 2007b).
Description: Thallus crustose, episubstratic, whitish to whitish grey, thin, continuous to rimose, smooth. Apothecia lecideine, sessile, black, epruinose, 0.4-0.8(-1) mm across, with a flat to slightly convex disc, and a thin, often shiny, persistent proper margin. Proper exciple 60-90 µm wide laterally, K-: epithecium brown to olive-brown; hymenium colourless, 100-150 µm high, densely inspersed with oil droplets; apical cells of paraphyses 1.5-2 μm thick at mid-level, the apical cells slightly swollen, (2.5-)3-4.5 µm wide; hypothecium dark brown. Asci 8-spored, Bacidia-type. Ascospores 1-septate, brown, ellipsoid, (23-)26-29(-32) x (9-)12-15(-16.5) µm, with subapically thickened inner wall and septum, pointed at apices, often curved, smooth, Callispora-type. Pycnidia black. Conidia cylindrical or narrowly ellipsoid, 3-3.5 x 1-1.5 μm. Photobiont chlorococcoid. Spot tests: thallus K+ yellow, C-, KC-, P- or P+ very faintly yellow, UV-. Chemistry: thallus with atranorin.
Note: a mild-temperate to humid subtropical species found on thin twigs of conifers in humid stands of the subalpine belt; probably overlooked in the Alps. For further details see Giralt & al. (2000).
Growth form: Crustose
Substrata: bark
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: rare
Oromediterranean belt: absent
Montane belt: absent
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

E. Pittao CC BY-SA 04
TSB 13973

P.L. Nimis CC BY-SA 4.0
TSB 13973

E. Pittao CC BY-SA 04
TSB 13973