Fucus spiralis

Spiral popweed

Authority: Linnaeus

Thallus mostly less than 12 cm (4.7 in) tall, dichotomously branched with a tendency to twist near the tips of branches; well-defined midribs run almost to the tips of branches but specialized air vesicles are lacking. Small, round or swollen receptacles have a rim of sterile tissue, and there are sterile surface cavities (cryptostomata) from which long colorless paraphyses protrude.

Habitat

Although not common, this species can form a narrow band above Fucus distichus, a species with which it can be easily confused, primarily on semi-exposed shores.

North Pacific Distribution

Aleutian Islands, Alaska to Central California.

Former scientific names

Fucus areschougii, Fucus vesiculosus var. spiralis, Halidrys spiralis

Similar taxa

Fucus distichus

References

AlgaeBase (opens in a new tab)

Last updated December 26, 2010