Lithothamnion phymatodeum

Thallus as thick calcareous crusts, tightly adhering to the substrate, of roundish or irregular shapes, 3.5-8 cm in diam., pinkish-purple, violet or whitish-pink with narrow or broadly cylindrical protuberances, 2-6 mm high and 2-4 mm in diam., covering the surface of the crust and giving them a “verrucose” appearance. Protuberances simple or subdichotomously branched, not fusing together, with rounded tops. Margins of the crust uneven, wavy or lobed, with white border, raised above substrate. Conceptacles protruding, to 500 mm across, with age turn whitish, usually develop on the protuberances. The roof of tetrasporangial conceptacle with (25-)30-40 pores. Carposporangial conceptacles with cone-shaped roof bearing one pore. Growing in the intertidal and upper subtidal zones, on stones, boulders and shells in semi-sheltered and open areas.

Pacific Ocean. Common in countries of the Asia-Pacific Region: China (Yellow Sea), Japan (Hokkaido Island), Korea and Russia (Sea of Japan, Sea of Okhotsk).