Rhizocarpon richardii Rhizocarpaceae
Rhizocarpon richardii

Growth type crustose
Chemical results: Medulla: K+/- yellow, usually C+ red, P+/- orange.

Usually coastal, found on siliceous pebbles, rocks and stable shingle.

Brown to greyish-brown, areolate-cracked thallus, often with purplish tinge. Fimbriate blackish-brown prothallus is often present. Innate, flattish black apothecia with thin margins. Spores 22-27 x 11-14 Ám, mainly 1-septate, but secondary septa sometimes occur. Epithecium K-, dark-green or grey.

Similar: Rhizocarpon hochstetteri and Rhizocarpon reductum are C-


Rhizocarpon richardii

Rhizocarpon richardii
Rhizocarpon richardii
On chert, Portland, Dorset. February 2016

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