Family Description:
Gametophytic plants consist of erect multiaxial branched axes. Monosporangia are sometimes formed on modified cortical cells. Tetrasporophytes are crustose, with irregularly zonate tetrasporangia occurring in sori.

Species description:
Bushy Ahnfelt's Seaweed is a tough, perennial and slow growing species that attaches to rocks. It is often found partly immersed in sand, and can survive considerable periods of time completely covered.

This species is dark, reddish purple to blackish and is densely tufted with tangled, solid branches up to 15 cm (6 in) tall. The branches are cylindrical and repeatedly fork dichotomously. They are stiff and wiry and only 0.25 to 0.5 mm in diameter. These erect branches grow from a prostrate, branched rhizome.

Reproductive structures occur in small knobs scattered on the branches.

Bushy Ahnfelt's Seaweed has been used in Russia to make agar.

Source:  North Pacific Seaweeds

Synonyms and Alternate Names:
Gigartina fastigiata