Family Description:
Most members of this family are flattened and branched or bladelike. They have an alternation of isomorphic generations. Cells of the female reproductive apparatus are relatively large and often lobed. Tetrasporangia are scattered in the outer cortex and are cruciately divided.

Species description:
The alternate, flattened branches tend to twist to produce a bushy growth form. One or more main axes, up to about 5 mm (0.2 in) in diameter at the base, are supported by a small discoidal holdfast attached to rocks. Although most specimens will be up to about 12 cm (4.7 in) tall, you can find an occasional specimen that is considerably larger. It is basically rose red in color. The branch tips are sharply pointed and the overall texture is somewhat firm.

Male and female gametophytes are separate individuals. The cystocarps develop as protruding bumps on the branches of the female gametophyte.

This species is quite variable in morphology, probably in response to environmental factors. For example, individuals with broader branches are found in more exposed habitats, while narrower forms come from either deeper waters or more sheltered locations.

Source:  North Pacific Seaweeds

Synonyms and Alternate Names:
Chondrococcus cristatus
Euthora fruticulosa
Fucus coccineus var. pusillus
Fucus cristatus
Nereidea cristata
Nereidea fruticulosa
Rhodymenia cristata
Sphaerococcus cristatus