Description: Large foliose blades, thin but tough, growing from a discoid holdfast to 60 cms long. Stipe short, 5 mm. Blades lobed up to 10 cms broad and 45 cms long pointed at the end, fleshy and elastic.

Habitat: Epilithic, rarely on Laminaria, sublittoral to 12 m deph.

Distribution: Known only from Ireland, Co. Cork and the Plymouth Sound in England.

Key Identification Features:

• Large, flat with short stipe. Blades bullate (bulging puckered appearance) with clear apical point to the blade.

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

iNaturalist: Cryptonemia hibernica at iNaturalist World Species Observations database.

WoRMS: Cryptonemia hibernica at World Register of Marine Species. Accepted name: Cryptonemia hibernica Guiry & L.M.Irvine, 1974. AphiaID: 145239.

Classification: Biota; Plantae; Biliphyta; Rhodophyta; Eurhodophytina; Florideophyceae; Rhodymeniophycidae; Halymeniales; Halymeniaceae; Cryptonemia