Hymeneliaceae Hymenelia prevostii Growth type crustose Chemical results negative Found on hard, damp, often horizontal limestone in natural situations and on church memorials. BLS conservation evaluation: LC NS The pinkish discs (translucent when wet) are immersed in pits in a whitish or creamy-brown thallus. The photobiont is trebouxioid so thallus does not scratch orange when wet. Spores simple, 10-24(-26) × 7-17(-19) µm. Pycnidia absent. Microscope photograph below. Similar: H. epulotica. Photobiont Trentepohlia, thallus scratches orange

Microscope photograph

Hymenelia prevostii
Lychett Matravers, Dorset. January 2014