Description: Thallus flat with prostrate foliose branches, very thin up to 5 mm wide and up to 5 cms long, overlapping. Veins microscopic.

Habitat: Sublittoral only, as patches on pebbles or rock. Generally on stones or gravel in a depth of 30 m.

Distribution: British Isles, mainly south-western coasts but recorded in Wales and on the north of Ireland and in Scotland. Europe: the Mediterranean, Portugal and Spain.

Similar Species: Acrosorium venulosum.

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

iNaturalist: Radicilingua thysanorhizans at iNaturalist World Species Observations database.

WoRMS: Radicilingua thysanorhizans at World Register of Marine Species. Accepted name: Radicilingua thysanorhizans (Holmes) Papenfuss, 1956. AphiaID: 144780.

Classification: Biota; Plantae; Biliphyta; Rhodophyta; Eurhodophytina; Florideophyceae; Rhodymeniophycidae; Ceramiales; Delesseriaceae; Nitophylloideae; Nitophylleae; Radicilingua