Schizymenia dubyi

Thallus blade-like, soft, fleshy, slippery, roundish or irregularly shaped, entire or split into lobes, 10-20(-40) cm long, 5-15(-25) cm broad, with widely cuneate base on short or inconspicuous stipe, with smooth or slightly undulate margins, purple-red to brownish-red color. In transverse section, cortex composed of subdichotomously branched filaments consisting of cells; the outermost cells oval, 3-5(7)×6-10 mm, inner cortex of larger roundish, oval to ovoid cells, 6-12×12-18 mm; and medulla composed of cellular filaments, to 10 mm diam. Cystocarps produced from inner cortex, 100-200 mm across. Tetrasporophyte crustose. Attachment by small disc-like holdfast. Growing on rocks, stones in the lower intertidal and upper subtidal zones of open coasts exposed to wave action.

Europe, China, Korea, Japan, Australia and New Zealand.