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Lichen: Lecanora muralis

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Lecanora muralis showing the high density of apothecia and the gaps in the central region of the thallus.

Lecanora muralis showing the high density of apothecia and the gaps in the central region of the thallus.

Name: Lecanora muralis (Schreb.) Rabenh.

Pronunciation: Lecanora muralis

Conservation Evaluation: Least Concern Body Type: Crustose

Lecanora muralis showing the placodioid prothallus.

Lecanora muralis showing the placodioid prothallus.

Description: The thallus tends to be circular, reaching diameters of about 10 cm; the central region is frequently ‘bald’ where the mature areoles die off. It is a particularly beautiful lichen with a greenish-yellow to greenish-brown thallus and a well defined lobed or placodioid prothallus. It may be slightly shiny or pruinose. The apothecia are clustered towards the centre of the thallus and are typically 0.5 mm to 1.5 mm in diameter, rarely reaching 2 mm.

The rim of the thallus is well developed and varies from being complete to crenulate to wavy (flexuose). Discs are yellow to yellow-brown and are a mixture of flat and convex; they are never pruinose. Ascus size is characteristically 30 to 40 µm by 10 µm; ascospores 10 to 15 µm by 4.5 µm.

Lecanora muralis showing the wavy rims on the apothecia.

Lecanora muralis showing the wavy rims on the apothecia.

Chemical Tests: Pd +(yellow), K -, KC +yellowish and C -.

Nature Notes: Seems to like man-made surfaces such as concrete, paving slabs and tarmac; also found on nutrient rich calcareous rocks. It is resistant to air pollution.

Vice County distribution map of Lecanora muralis: See Map

map-lecanora-muralis

Link: Map this species on the Lichen Survey

Other species recorded in Ireland

  • Lecanora achariana A.L.Sm.
  • Lecanora actophila Wedd.
  • Lecanora agardhiana Ach.
  • Lecanora aitema (Ach.) Hepp
  • Lecanora albella (Pers.) Ach.
  • Lecanora albescens (Hoffm.) Branth & Rostr.
  • Lecanora alboflavida Taylor
  • Lecanora andrewii de Lesd.
  • Lecanora argentata (Ach.) Malme
  • Lecanora campestris (Schaer.) Hue
  • Lecanora carpinea (L.) Vain.
  • Lecanora cenisia Ach.
  • Lecanora chlarotera Nyl.
  • Lecanora conferta (Duby ex Fr.) Grognot
  • Lecanora confusa Almb.
  • Lecanora congesta Clauzade & Vezda
  • Lecanora conizaeoides Nyl. ex Cromb.
  • Lecanora crenulata Hook.
  • Lecanora dispersa (Pers.) Sommerf.
  • Lecanora epanora (Ach.) Ach.
  • Lecanora epibryon (Ach.) Ach.
  • Lecanora expallens Ach.
  • Lecanora farinaria Borrer
  • Lecanora fugiens Nyl.
  • Lecanora gangaleoides Nyl.
  • Lecanora helicopis (Wahlenb.) Ach.
  • Lecanora horiza (Ach.) Linds.
  • Lecanora intricata (Ach.) Ach.
  • Lecanora intumescens (Rebent.) Rabenh.
  • Lecanora jamesii J.R.Laundon
  • Lecanora orosthea (Ach.) Ach.
  • Lecanora persimilis (Th.Fr.) Nyl.
  • Lecanora piniperda Körb.
  • Lecanora poliophaea (Wahlenb.) Ach.
  • Lecanora polytropa (Hoffm.) Rabenh.
  • Lecanora praepostera Nyl.
  • Lecanora pulicaris (Pers.) Ach.
  • Lecanora rugosella Zahlbr.
  • Lecanora rupicola (L.) Zahlbr.
  • Lecanora saligna (Schrad.) Zahlbr.
  • Lecanora sambuci (Pers.) Nyl.
  • Lecanora soralifera (Suza) Räsänen
  • Lecanora stenotropa Nyl.
  • Lecanora subcarnea (Lilj.) Ach.
  • Lecanora sulphurea (Hoffm.) Ach.
  • Lecanora symmicta (Ach.) Ach.
  • Lecanora varia (Hoffm.) Ach.

Text and images © Paul Whelan, 2009.