Photo: Fucus vesiculosus 1.

You can't see much of the Fucus, but wow, that water surface looks cool. Rymättylä, Finland. Wild. 2000-08-02.

Fucus vesiculosus L.
Engl.: bladderwrack, black-tang, bladder fucus, bladder wrack rockweed, cutweed, dyer's fucus, fucus, kelp-ware, lady wrack, meeriche, popping wrack, red fucus, rockweed, sea ware, sea-wrack, swine tang.
Deu.: Blasentang.
Suom.: rakkolevä.
Sven.: blåstång, hötter, klotång.
Ital.: quercia marina.
Pharm.: aethiops vegetabilis, vegetable ethiops