Sinonimi: Amphiroa verrucosa Kützing (1843) p. 387; Amphiroa verruculosa Kützing (1849) p. 700; Amphiroa rubra (Philippi) Woelkerling (1983) p.173.

CARATTERI VEGETATIVI

Thallus habit: erect, bushy; endophytic base on other calcareous algae (particularly on Lithophyllum species). Size: 2-4cm high. Branching: dichotomous, regular (A) and "geometric" (angle of about 90°); branch junctions usually not coinciding with intergenicula. Branches lying on different planes, slightly swollen apices. Intergenicula: cylindrical with rare annular swellings, tapered on upper part of fronds (1-4 (4.5)mm long, 0.25-0.6mm in lower diameter, upper diameter 0.15-0.18mm). Genicula: 1 row of medullary cells (120-160µm long) with ends reed-like. Colour of living specimen: dark red to pink violet (rare), apart from lighter apices due to annular ridges. Colour of dried specimen: as previous (rarely lighter colours).

Medulla: 1 row of long cells: 75-160(190)µm long with an alternation of 1 row of short cells: (20)30-70µm long; cells near genicula 10-35µm long. Cortex: 10-40µm thick; cells 7-10µm long, in distinct rows. Cell connections: secondary pit-connections.

Gametangial conceptacles: spermatangial conceptacles slightly raised, hemispherical; 200mm in diameter. Tetra/bisporangial conceptacles: lateral, hemispherical, raised; 300-400mm in diameter x 100-200mm high. Phenology: August, September.

Alboran Sea (A): Spain, 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, Albania; : Italy, Libya, Israel; Middle Eastern Mediterranean Sea (L): Italy, Greece, Turkey, Syria; North Eastern Mediterranean Sea (M): Greece, Turkey.