Irish lichens

Clauzadea monticola

Order: Lecanorales       Family: Porpidiaceae

Species: Clauzadea monticola

Growth type crustose. Left identified by J Douglass
Photos: On concrete walls. Co. Cork, SW Ireland.

Thallus dark grey or grey-brown, +/- immersed, prothallus absent. The sessile, convex black apothecia become reddish when wet but are never pruinose. Can resemble perithecia when dry. Hypothecium is reddish-brown. Asci 8-spored with simple, colourless, thin-walled spores, (6-)8-12(-14) x 4-9 Ám. Microscope photograph below.
Chemical reactions negative

Common and widespread on calcareous rocks and mortared walls.

Similar: Lecidella stigmatea: Thallus K+/- yellow. Hypothecium colourless or pale yellow. Sarcogyne regularis: Pruinose discs reddish when wet. Multi-spored ascus.

Clauzadea monticola

Microscope photograph
Clauzadea monticola
Clauzadea monticola January and April 2012

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