Description: Thin sheets, up to 10cms across, but smaller typically. Deep orange or red. Soft. Oscules may not be apparent. Pores in oval pore-sieve areas with smooth tissue between.

Habitat: On bedrock and boulders, usually in deep water below 25m depth, but originally described from a cave in the intertidal zone. On horizontal rock in clear water.

Distribution: West coast of Ireland and Scotland, this is the commonest Hymedesmia species in diving range in these areas.

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

iNaturalist: Hymedesmia jecusculum at iNaturalist World Species Observations database.