Pseudocyphellaria intricata

This is a substantial foliose lichen with, when moist, a brown (café au lait) thallus that becomes grey-brown on drying out. Its surface is smooth, though it may develop rather weak ridges. The purple grey coloured eruptions of soralia along the lobe margins may spread as scattered dots or somewhat more elongated squiggles over the surface of the thallus. They are a prominent feature. It might be mistaken for a Sticta, Nephroma or a Peltigera.  The undersurface of Pseudocyphellaria and Sticta is covered in a dense, dark brown stubble of rhizines amongst which are small sunken bald patches, called pseudocyphellae in this species and give it its generic name and the English name of the Americans-the speckle bellies and true cyphellae in Sticta. In practice the differences between theses structures can only be observed with difficulty under a microscope. In Sticta limbata the undersurface and rhizines are much paler in colour and the rhizines less well developed and the lobes tend to be more or less circular in outline and remain discrete. P. intricata develops somewhat elongate overlapping lobes. S. sylvatica smells of fish when wet.   Peltigera has large bushy, rather widely spaced rhizines and Nephroma a bare undersurface. 

Photo: Ray Woods

PLEASE NOTE. All Pseudocyphellarias appear to be exceptionally rare in Wales and you must not just rip up bits to look at the underside!! In dry weather take a small sprayer and water with you to moisten the thallus before carefully turning it over in situ. An illuminated hand lens is almost a must.

There have been three Pseudocyphellaria species recorded from Wales. All have white medullas.  P. norvegica differs in having a C+ red and KC+ orange medulla and soralia. Its lobes are somewhat more rounded and ridged than the superficially similar P. intricata and there are more soralia scattered over the thallus surface. P. intricata  tends to have more elongated smooth lobes with the soralia, at least initially, confined to the lobe margins. P. lacerata has cylindrical to branched isidia at the lobe margins and occasionally spreading over the lobe surface. Unfortunately occasionally P. lacerata soredia can grow in situe to develop a cortex and so resemble isidia. If in doubt seek expert help.