Common names:
Dúlamán; Múirín na Muc; Caisíneach (Irish); Channeled Wrack (English)
Description:
Plants 80-120 mm long, yellow-brown in colour, turning black when dry, and often so dry that the fronds disintegrate when trodden upon; regularly dichotomously branched with a distinct channel on the underside (the side nearest the rock), which holds moisture and apparently helps the wrack to survive at very high levels on the shore. Reproduction in conceptacles visible as dots on warty terminal receptacles. Usually infected by a fungus which may assist in allowing it to survive high in the intertidal.
Habitat:
Occurring very high on the shore, generally above MHWN, on wave-exposed and sheltered shores, but absent from very exposed rocky shores. Some free-living ecotypes (var. libera) occur in salt-marshes.
Similar species:
No other wrack has the distinct channeling of Pelvetia.
Key characteristics:
Channeled frond, regular dichotomies, height on shore.
Distribution:
Confined to the NE Atlantic from the Faroes south to Portugal.