Calicium victorianum  

Thallus: a thin crust, almost inconspicuous, greyish white, usually immersed, ca 200 µm thick, not well delimited, with 7-10 µm diam., chlorococcoid algae as photobiont.
Anamorph: not known.
Teleomorph: Ascomata black, non-pruinose apothecia, appearing sessile, but with a short stalk no taller than 100 µm. Capitulum, bell-shaped, (195-) 235-400 (-500) µm diam., with a distinct dark brown mazaedium, which sometimes appears bluish-grey due to the presence of colourless thin hyphae amongst the ascospores. Exciple lecideine, carbonised, dark brown to black, 45-65 µm wide, consisting of tightly compressed isodiametric cells, with carbonised lumen, 4-5 µm diam., forming a prosoplectenchyma, non-continuous below the hypothecium. Hypothecium dark brown, becoming carbonised, 120 µm high at its widest point. Epithecium not observed. Asci cylindrical, ca 70 x 5-5.5 µm, but difficult to observe, unitunicate and soon evanescent, 8-spored. Ascospores broadly ellipsoidal, initially uniseriately arranged within the ascus, pale brown and aseptate, but when matured and forming the mazaedium become darker brown, 1-septate, only slightly constricted at the septum, thick walled and ornamented, (9-) 11-13 × 4-6 µm.
Chemistry: The species contains physodalic acid (a β-orcinol depsidone) as a major component, but this was detected only by HPLC analysis from the apothecia. All spot tests carried out on the thallus and apothecia were negative. The more characteristic lichen substances in the Caliciaceae such as pulvinic acid derivatives and anthraquinone could not be detected in this species.