Bladder wrack  (Fucus vesiculosus)

Learn about the scientific name of this species and how it fits into the tree of life at Nature Navigator.

Description

Bladder wrack is a familiar large olive-brown coloured seaweed (3), which attaches to rocky substrates by means of a small disc (4). The flattened, branching fronds, which grow up to 2m in length, have an obvious midrib, and are covered with spherical air bladders, which tend to occur in pairs on either side of the mid-rib (3). In small plants, however, air bladders may be entirely absent (3). Forked and pointed reproductive structures occur at the tips of the fronds (3). The appearance of bladder wrack varies depending on the environmental conditions in which it occurs; in more sheltered areas there are many air bladders, whereas there are fewer in more exposed conditions (3). In very exposed areas, a form of bladder wrack called Fucus vesiculosus forma linearis may arise, which completely lacks bladders (3).

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