Distribution: C - Laz (TSB 36478), Sar (Tretiach & al. 2009). S - Camp (Tretiach & al. 2009), Cal (CLU 12239), Si (Tretiach & al. 2009).
Description: Thallus leprose to subcrustose, generally well-delimited and forming regular, confluent rosettes, dirty white to pale grey with a bluish tinge, (0.16-)0.25-0.35(-0.47) mm thick, the margins distinct, usually well-developed, with a raised, thick rim. Cortex absent; hypothallus generally poorly developed, formed by light brown hyphae, K-; prothallus absent. Central part of thallus granular, tightly attached to the substratum the granules soredia-like, ellipsoid to irregularly shaped, up to (0.22–)0.28-0.35(-0.65) mm in diam., devoid of crystals, surrounded by a weft of up to 100 µm long, hyaline, projecting hyphae; hypothallus compact, composed of tightly intertwined hyphae. Photobiont chlorococcoid. Spot tests: K+ yellow-brownish, C-, KC-, P+ orange, UV- or UV+ pink. Chemistry: different chemotypes: 1) atranorin, roccellic acid, zeorin, stictic and constictic acids; 2) atranorin, UV+ vivid pink unknown, stictic and constictic acids; 3) atranorin, roccellic acid, stictic and constictic acids; 4) atranorin, roccellic acid, stictic and constictic acids, fumarprotocetraric or protocetraric acids; 5) atranorin. roccellic acid, protocetraric acid; 6) atranorin, roccellic acid, protocetraric acid, fumarprotocetraric acid; 7) atranorin, roccellic acid, fumarprotocetraric acid.
Note: on siliceous soil and on terricolous mosses, more rarely directly over siliceous rocks, in sheltered situations but in sunny and arid habitats, with optimum in the Mediterranean belt; probably more widespread in southern Italy. The type of L. lobificans Nyl. proved to be identical with L. santosii, but the name was widely used to designate L. finkii (Lendemer 2013).
Growth form: Leprose
Substrata: soil, terricolous mosses, and plant debris
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly asexual, by soredia, or soredia-like structures (e.g. blastidia)