Hypotrachyna Parmeliaceae
Hypotrachyna britannica

Identification is uncertain

Growth type foliose
Chemical results: Cortex K+ yellow. Medulla K-, C+ red, KC+ red, P-, UV-

Often coastal on sheltered, well-lit siliceous rocks. Specimens on trees (including these shown here) are probably Hypotrachyna afrorevoluta.

Whitish-grey or pale bluish-grey lobes, the tips often brownish and +/- ascending. Under surfaces dark-brown or black with paler margins, rhizines simple or tufted, marginal cilia rare. Medulla white. Sub-marginal bluish-black soredia develop from pustules on lobes. Apothecia are absent.

On Birch. Holton Lee, Dorset. October 2012

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