Wrack (seaweed)

Fucus serratus, "toothed wrack"

Pelvetia canaliculata, "channelled wrack"

Wrack is part of the common names of several species of seaweed in the family Fucaceae. It may also refer more generally to any seaweeds that wash up on beaches and may accumulate in the wrack zone.^[1]

It consists largely of species of Fucus — brown seaweeds with flat branched ribbon-like fronds, characterized in F. serratus by a saw-toothed margin and in F. vesiculosus, another common species, by bearing air-bladders. Another component of sea wrack may be Zostera marina, so-called sea-grass, a marine flowering plant with bright green long narrow grass-like leaves.^[2]

• "Bladder wrack", Fucus vesiculosus
• "Channelled wrack", Pelvetia canaliculata
• "Knotted wrack", Ascophyllum nodosum
• "Spiral wrack" or "flat wrack", Fucus spiralis
• "Toothed wrack" or "serrated wrack", Fucus serratus

Historically wrack was used for making manure, and for making "kelp",^[2] a form of potash.^[3]

References

•  This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). "Seawrack". Encyclopædia Britannica 24 (11th ed.). Cambridge University Press. p. 566.