Synonyms: Evicentia chrysocardia (Poelt & M. Steiner) Barreno comb. inval.
Distribution: N - Piem (Obermayer 2002), VA (Piervittori & Isocrono 1999, Matteucci & Vanacore Falco 2015).
Description: Thallus crustose-subsquamulose, episubstratic, 0.5-1 mm thick, greenish white to pale greenish yellow, sometimes intensely yellow-green, often more or less pruinose, forming up to 10 cm wide patches, usually starting the life-cycle on the thalli of Diploschistes scruposus s.lat. Areoles 1.5-5 mm wide, rounded or more ore less angular, flattened, attached by more or less distinct rhizines. Cortex 15-70 µm thick, the upper part greenish yellow, the lower part colourless; epinecral layer more or less developed; algal layer more or less continuous; medulla yellow, especially around the apothecia. Apothecia lecanorine, 0.4-2 mm across, usually 1 per areole, with a round to irregular, brown, at first smooth, then rugose disc, and an evident, not or only slightly raised thalline margin. Epithecium brown; hymenium colourless but inspersed with yellowish granules, 100-140 µm high; paraphyses 1.5-2.5 µm thick at base; hypothecium colourless. Asci 100-200-spored, broadly ellipsoid, the apical dome K/I-. Ascospores 1-celled, hyaline, globose or subglobose, 3-5.5(-9) x 3-4.5(-7) µm. Photobiont chlorococcoid. Spot tests: K- or K+ yellow turning red, C-, KC-, P-, UV+ orange. Chemistry: rhizocarpic acid, and variable amounts of norstictic acid.
Note: on base-rich siliceous rocks in dry-warm Alpine valleys, growing on the thalli of Diploschistes scruposus below the subalpine belt. Hitherto known only from the western Alps and Catalonia (Roux in litt.), and certainly worthy of protection.
Growth form: Crustose
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual
Subcontinental: restricted to areas with a dry-subcontinental climate (e.g. dry Alpine valleys, parts of Mediterranean Italy)