Phaeophyta - Brown Algae


Multicellular PLANTAE with uniserate, unbranched and branched filaments, tufts of filaments or multiaxial branching systems. Most produce parenchymatous thalli that are large, macroscopic leathery, rubbery or tough, several with root-like, stem-like and leaf-like structures; all but a few are attached.

The size of Bermuda's species range from microscopic to 80 cm, the colour from brown or yellow-brown to olive-brown, dark brown and almost black.

Only a single class, Phaeophyceae, is presently recognized, and is almost exclusively marine. Somewhat under 1500 species are known. 30 genera encompassing over 60 species have been reported from Bermuda. The present account includes 6 species.


Brown algae are the most conspicious seaweeds along rocky coasts in both northern and southern hemispheres. Not as numerous or large in tropical waters as in more northern or southern latitudes; they frequently occur attached firmly to rocks; intertidal zone or subtidally.

Biology and Reproduction

The brown algae undergo an alteration of sporophyte with gametophyte generations.