Phylum: Rhodophyta   Family: Bangiaceae

Porphyra dioica J. Brodie & L.M. Irvine, 1997

Purple Laver; Sloke

On intertidal rocks, hanging down from a short stipe and holdfast. Commonest in spring and early summer. Depending on the light, the colour is olive-green to brown-purple, and can even look black at times

References: 
Brodie & Irvine (2003)- Seaweeds of the British Isles, Volume 1 Rhodophyta, Part 3B Bangiophycidae