Collemataceae Scytinium plicatile (Leptogium plicatile) Growth type foliose. Chemical results negative Usually on hard, damp limestone and horizontal tombstones but occasionally found on siliceous rocks affected by calcareous seepage. Variable. Convoluted dark olive-brown or red-brown thallus, loosely rosette-shaped and closely adpressed. Thick, tough, +/- ridged lobes with divided, pleated margins (most noticable when dry). Coarse, isidia-like warts sometimes present, apothecia infrequent. Microscope photographs below, showing lattice of cortical cells. Similar: Collema auriforme becomes jelly-like when wet.

Microscope photographs



Scytinium plicatile (Leptogium plicatile)
St. Nicholas, Arne, Dorset. February 2014