views updated

Ectocarpales (division Phaeophyta) An order of brown seaweeds in which the thallus is usually composed of two parts: a prostrate disc which functions as a holdfast, and an erect thallus which may be filamentous, foliose, or bulbous. There are many families. They are found mainly in the intertidal zone, attached to rocks or to other seaweeds.