Synonyms: Melobesia pustulata Lamouroux (1816) p. 315; Dermatolithon pustulatum (Lamouroux) Foslie (1899) p. 11; Lithophyllum pustulatum (Lamouroux) Foslie (1904) p. 8; Epilithon pustulatum (Lamouroux) Lemoine (1921) p. 10; Tenarea pustulata (Lamouroux) Adey (1965) p. 88 (comb. invalid.).

VEGETATIVE FEATURES

Thallus habit: encrusting, closely adherent, without excrescences, orbicular or kidney-shaped, sometimes forming sleeves. Margin growing thin until mixing with the substratum; edge often difficult to be observed. Size: 1-2(3)cm diameter, thickness 0.1-0.6mm. Colour of living specimen: bright pink mauve. Colour of dried specimen: pale grey.

Basal crust: multistratose. Basal filaments: unilayered, palisade cells, with more or less sinuate cell walls (A): 10-21µm long x 30-40 (65)µm in diameter. Erect filaments: multilayered, 2-4 (8) cells quite regular: (10)18-45 (60)µm long x 6-20µm in diameter. Epithallial cells: cells of the same length, flattened, triangular or domed (B). Cell connections: secondary pit-connections. Other features: trichocytes occasionally present (in basal cells). 

Gametangial conceptacles: carpogonial 200-275µm in diameter, spermatangial --- Tetra/bisporangial conceptacles: uniporate (C), hemispherical-conical or warty: 300-500µm diameter x 145-195µm high. Phenology: ---

Habitat: epiphytic, rarely epizoic, recorded especially on leaves and rhizomes of seagrasses, on Hydrozoans and Molluscs. Often occurring in association with Hydrolithon farinosum, Corallina officinalis, C. elongata, Jania rubens, J. longifurca and on other algal species: Laminaria, Cystoseira, Sargassum, Valonia, Dilophus, Cladophora, Phyllophora, Gigartina, Gelidium, Gymnogongrus, Laurencia. Bathymetric distribution: littoral up to 10 depth. Geographic distribution (Babbini & Bressan 1997):

Alboran Sea (A): Spain, Morocco; Western Mediterranean Sea (African shores) (B): Algeria; Tunisia; Middle Western Mediterranean Sea  (C): Spain, Italy; North Western Mediterranean Sea  (D): Spain, France, Italy; North Adriatic Sea (E): Italy, Slovenia, Croatia; Middle Adriatic Sea (F): Italy, Croatia; South Adriatic Sea (G): Italy; South Eastern Mediterranean Sea (H): Italy, Malta, Tunisia, Libya; Middle Eastern Mediterranean Sea (L): Greece, Syria, Turkey; North Eastern Mediterranean Sea (M): Greece, Turkey.