Description: Thallus monosiphonous with erect cylindrical fronds to 19 cms long. Branching irregularly alternate and at very narrow angles, each branch with a rounded apex. Cells large visible to the naked eye

Habitat: Very rare. Epilithic in the sublittoral to 3 m depth.

Distribution: A southern species recorded from England in Devon and Cornwall also Scilly Isles and the Channel Isles. Europe: the Mediterranean, Portugal, Atlantic coasts of Spain and France. Further afield: Canary Islands.

Similar Species: Griffithsia and Halurus.

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

iNaturalist: Bornetia secundiflora at iNaturalist World Species Observations database.

WoRMS: Bornetia secundiflora at World Register of Marine Species.