Irish lichens

Pertusaria amara

Order: Pertusariales       Family: Pertusariaceae

Species: Lepra amara (Pertusaria amara)

Growth type crustose.
Photos: On Oak and rock. Co. Cork and Co. Kerry, SW Ireland

Very variable. Thallus thick or thin, grey, +/- zoned at margins with punctiform soralia +/- regularly scattered over surface. Whitish farinose soredia with persistent very bitter taste. (Test with just a few grains on a moist finger.) Apothecia very rare.

Usually found on deciduous trees, occasional on conifers and rocks. Widespread throughout Ireland but most frequent in eastern half.
Soralia and medulla K-, C-, KC+ violet (fleeting), P+/- red, UV-
Positive taste test for oxalic acid is unmistakeable.

Similar: Pertusaria albescens, taste test negative.

Pertusaria amara

Pertusaria amara

Pertusaria amara
Pertusaria amara January and November 2010

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