Description: A small alga up to 10 cms long. Central axis surrounded by a cortex with alternately branched pinnate thalli. Very bushy and rigid.

Habitat: Epilithic and epiphytic in shaded pools of the low littoral and in the sublittoral to 20 m.

Distribution: Recorded from almost all shores of the British Isles but mainly western from the Shetlands to the Channel Islands. Europe: Mediterranean, Azores, Portugal, Atlantic coasts of Spain and France. Further afield: Morocco, Madeira, Salvage Islands, the Canary Islands, Japan, South Africa, Oman and New Zealand.

Similar Species: Sphacelaria plumosa and Stypocaulon scoparium.

Key Identification Features:

• Regular alternate branching.

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

iNaturalist: Halopteris filicina at iNaturalist World Species Observations database.

WoRMS: Halopteris filicina at World Register of Marine Species. Accepted name: Halopteris filicina (Grateloup) Kützing, 1843. AphiaID: 145906.

Classification: Biota; Chromista; Harosa; Heterokonta; Ochrophyta; Phaeophyceae; Dictyotophycidae; Sphacelariales; Stypocaulaceae; Halopteris