Description: Seen only in South Kerry V. scabra is an aquatic, subgelatinous Verrucaria of submerged rocks in rivers, streams and lakes. It has come to the attention of British and Irish lichenologists relatively recently (2005). Earlier collections may be named V. rheitrophila. Both species can have a quite densely pigmented thallus with a scatter of small black dots (punctae). V. scabra is the greener species with slightly roughened surface and spores often exceeding 15µm long, V. rheitrophila is brown with most spores never exceeding 15µm long. Collections of shaded material should be avoided.

Key Identification Features:

• Like V. rheitrophila but with green pigmentation of the thallus (not brown), larger spores, more widely spaced discs and slightly roughened surface
• Submerged rocks in acid streams.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Hydropunctaria scabra at iNaturalist World Species Observations database.