Description: Thallus erect to 30 cms polysiphonous with 9-10 periaxial cells. Branched irregularly in one plane irregularly alternate. Ultimate ramuli monosiphonous and formed in "pincer-like" pairs.

Habitat: Epilithic in low littoral rock pools and sublittoral to 33 m.

Distribution: Widely distributed around the British Isles including the Shetlands and the Channel Islands. Europe: Portugal, Spain, France, the Baltic and Norway.

Key Identification Features:

• Ultimate ramuli monosiphonous and formed in "pincer-like" pairs.

Distribution Map from NBN: Heterosiphonia plumosa at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Heterosiphonia plumosa at iNaturalist World Species Observations database.

WoRMS: Heterosiphonia plumosa at World Register of Marine Species. Accepted name: Heterosiphonia plumosa (J.Ellis) Batters, 1902. AphiaID: 144732.

Classification: Biota; Plantae; Biliphyta; Rhodophyta; Eurhodophytina; Florideophyceae; Rhodymeniophycidae; Ceramiales; Delesseriaceae; Heterosiphonioideae; Heterosiphonia