Description: Thallus erect, axes rising from stolonous holdfast and grows to 15 cms high, compressed with terminal groove. Branches irregularly alternate.

Habitat: Abundant. Epilithic in rock pools from mid-littoral to low water but not sublittoral.

Distribution: Generally distributed around the British Isles From the Shetlands to the Channel Islands. Europe: Mediterranean, Azores, Portugal, Atlantic coasts of Spain and France, Norway. Further afield: the Canary Islands, Morocco, Packistan, Omen and Ymen,

Similar Species: Osmundea osmunda has a discoid holdfast.

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

iNaturalist: Osmundea pinnatifida at iNaturalist World Species Observations database.

WoRMS: Osmundea pinnatifida at World Register of Marine Species. Accepted name: Osmundea pinnatifida (Hudson) Stackhouse, 1809. AphiaID: 144847.

Classification: Biota; Plantae; Biliphyta; Rhodophyta; Eurhodophytina; Florideophyceae; Rhodymeniophycidae; Ceramiales; Rhodomelaceae; Laurencieae; Osmundea