Forest and undergrowth of the sea

Sea Rimu     Paddle weed     Bull kelp     Bladder kelp     Venus necklace     Flapjack

Sea Rimu

(Caulerpa brownii)

Identification: A long, thin leafed weed with fronds looking like the sprays from the rimu tree. Rimu is the Maori name for seaweed.

General: Found around low water mark.


Paddle Weed

(Eklonia radiata)

Identification: A brown, flat leafed and bodied weed. It has no floats and has a rounded stalk.

General: Very abundant. Reaches a length of 2 m. Found just below low water on rocky coasts, often with many plants growing together.


Bull Kelp

(Durvillea antarctica)

Identification: Has a large, tough holdfast fixed tightly to the rock. Has a rounded stalk which expands into wide, heavy blades, then into whip-like thongs. May grow to 10 m.

General: Found on the most exposed, surf lashed, rocky shores.


Bladder Kelp

(Macrocystis pyrifera)

Identification: May live in deep water (to 18 m) and grow to 24 m. Holdfast has a complex branching structure like the roots of a tree. Has a round stalk and flat fronds with floats at their base.

General: A real giant of the seaweed world. May form very extensive beds like a marine forest.


Venus Necklace

(Hormosira banksii)

Identification: A brown seaweed consisting of a chain of brown balls. Found in the mid-tidal area on open rock platforms or in rock pools.

General: A common seaweed, generally living in areas protected from strong wave action. Commonly grows with many plants together.



(Carpophyllum flexuosum)

Identification: A long thin brown weed, the main stem having the appearance of a series of jointed sections. Short fronds and the occasional float extend from the main stem.

General: Occurs in sheltered harbours, rock pools and open coasts. The stem and fronds are stiff, with numerous oval, solid floats. The flexible flapjack species has rounded floats and fronds which have a slight midrib.

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