Synonyms:Lithothamnium ramulosum Philippi (1837) p. 388; Melobesia fruticulosa (Kützing) Decaisne (1842) p. 126; Spongites ramulosa Kützing (1869) p. 35; Lithothamnium fasciculatum ß fruticulosum (Kützing) Hauck (1883) p. 274; Lithothamnium meneghianum Vinassa (1892) p. 57; Lithothamnium fruticulosum (Kützing) Foslie (1895) p. 46; Paraspora fruticulosa (Kützing) Heydrich (1900) p. 315.

VEGETATIVE FEATURES

Thallus habit : more or less flattened and adherent or with branch-like protuberances. Size: 0.3-30mm thick. Colour of living specimen: dull red. Colour of dried specimen: yellow ivory.

Basal filaments: one or more filaments, layers more or less parallel to substratum. Ovoid to rectangular cells: 5-35µm long x 5-16µm in diameter. Erect filaments: filaments more or less orientated at right angle to the substratum, cells ovoid to elliptical. Epithallial cells: isodiametric or horizontally elongated (B). Cell connections: cell fusions (A).

Gametangial conceptacles: spermatangial flush with surrounding thallus surface; 235-335µm in diameter x 145-245µm high; carpogonial conceptacles slightly raised or at thallus surface level; 575-595µm in diameter x 295-320µm high. Tetra/bisporangial conceptacles: uniporate, slightly raised (C); 350-595µm in diameter x 275-410µm high. Columella frequently present. Phenology: Penrose (1991) observde that in the South Australian populations, the summer collected thalli are tetrasporophytic, gametophytic and/or carposporophytic. While during winter there are only tetrasporophytic plants. 

Habitat: epilithic species, sometimes free-living. Bathymetric distribution: littoral to sublittoral. Geographic distribution (Babbini & Bressan 1997):

Alboran Sea (A): Morocco; Western Mediterranean Sea (African shores) (B): Algeria, Tunisia; Middle Western Mediterranean Sea  (C): Spain, France, 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, Tunisia, Libya; Middle Eastern Mediterranean Sea (L): Greece, Turkey; North Eastern Mediterranean Sea (M): Greece, Turkey.