information on the biology of species and the ecology of habitats found around the coasts and seas of the British Isles

A lichen (Verrucaria mucosa)

Distribution data supplied by the Ocean Biogeographic Information System (OBIS). To interrogate UK data visit the NBN Atlas.
Only coastal and marine records shown



A thin, encrusting lichen forming bright bottle-green to dark olive green patches on mid shore to lower shore rocks. The thallus is smooth, oily or slightly irregularly cracked in appearance with a white edge around the margin. The thallus may be up to 30cm across. Small, black fruiting bodies are embedded in the thallus and become slightly raised when dry.

Recorded distribution in Britain and Ireland

Widely distributed around Britain and Ireland on rocky shores but not recorded from the shores of south east England, probably due to a lack of suitable substrata.

Global distribution



Found on well lit rocks from the middle to the lower shore. Rarer on wave sheltered shores.

Depth range


Identifying features

  • Thallus bright bottle-green to dark olive green in colour.
  • Thallus bears a white margin (prothallus).
  • Small, black fruiting bodies (perithecia) embedded in thallus when wet and raised when dry.

Additional information

May be confused with Verrucaria maura or Verrucaria striatula. Verrucaria striatula is similar but bears elevated black dots or ridges and prominent black fruiting bodies. Verrucaria maura has a matt black, cracked encrusting thallus with numerous small black fruiting bodies and occurs from just below to above high water level.

Listed by

- none -

Further information sources

Search on:


  1. CABI Bioscience, 2000. Index Fungorum Database. [On-line], 2002-04-23

  2. Dobson, F.S., 1997. Lichens of Rocky Shores. [Foldout pamphlet]. Shrewsbury: Field Studies Council.

  3. Dobson, F.S., 2000. Lichens: an illustrated guide to the British and Irish species. Slough: The Richmond Publishing Co. Ltd.

  4. Fletcher, A., 1980. Marine and maritime lichens of rocky shores: their ecology, physiology, and biological interactions. In The Shore Environment, vol. 2: Ecosystems (ed. J.H. Price, D.E.G. Irvine & W.F. Farnham), pp. 789-842. London: Academic Press. [Systematics Association Special Volume no. 17(b)].


This review can be cited as:

Tyler-Walters, H., 2002. Verrucaria mucosa A lichen. In Tyler-Walters H. and Hiscock K. (eds) Marine Life Information Network: Biology and Sensitivity Key Information Reviews, [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 14-08-2018]. Available from:

Last Updated: 10/07/2002