Ochrophyta · Brown Seaweed

Fucus distichus

Linnaeus
Phylum
Ochrophyta
Class
Phaeophyceae
Order
Fucales
Family
Fucaceae

Fucus distichus

Rockweed

Authority
Linnaeus
Thallus of this very common and abundant intertidal species is yellow-brown to medium brown, with a discoidal holdfast, flattened, straplike blades with midribs, which repeatedly branch more or less equally (dichotomous branching), and distinctive air bladders (receptacles) at reproductive maturity. Individuals grow up to 50 cm (20 in) tall.

Habitat

This perennial can dominate high to low intertidal rock from estuarine to semi-exposed habitats. Rockweed is very tolerant of fresh water and freezing temperatures.

North Pacific Distribution

Arctic Ocean, Bering Sea and Aleutian Islands, Alaska to central California; Japan; Russia

Former scientific names

Fucus evanescens, Fucus furcatus, Fucus gardneri, Fucus distichus subsp. evanescens

Similar taxa

Fucus spiralis usually occurs above Fucus distichus where they co-occur.

Last updated December 26, 2010

Photos