Collemataceae Blenothallia crispa (Collema crispum) Growth type foliose Chemical results negative Common on damp, shady calcareous rocks, walls and crumbling mortar, less frequent on shell sand and soil. Thin green-brown to blackish overlapping lobes, the margins +/- ascending, wavy, entire or crenate. Lobes only slightly swollen when wet. Globular isidia become flattened and squamulose and resemble small lobes. Apothecia are infrequent, flat and often with lobules on the margins. Thallus can be tinged emerald-green when wet or in shaded habitats.

Collema crispum
Canford Cliffs and Wimborne, Dorset. 2013 and 2014. Fertile specimen Canford Magna, January 2016