The sea sorrel is a filamentous and branched alga that resembles dirty long hair. However, if one looks carefully, one can see that this is brown algae and its leaves have become a kind of thorns.
The sea sorrel attaches to rocks or boulders and can reach up to 2 meters in length.
It is found all around Iceland and throughout the North Atlantic from New Jersey to Baffin Island in the west and from Portugal to northern Norway in the east.
There are no uses known for curly hair, sailors find it rather annoying as it often is entangled in nets.