Knotted wrack and its reproductive organs

Knotted wrack-receptacles

The reproductive organs (receptacles) became mature from late spring to early summer. Sexual identification is possible only when the receptacles are very mature. The receptacles of both sexes became more yellow as maturity progresses, but it is the male receptacles that became golden yellow to orange in colour. This means that the plant pictured above is probably a male. Soon after that the receptacles have withered and died during the summer, new ones grow.
   A fifteen-spined stickleback is also visible in the picture above.
   Knotted wracks life cycle resembles bladder wracks.

Knotted wrack     Other names
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Bo Johannesson | Martin Larsvik | Lars-Ove Loo | Helena Samuelsson