Bulletin of the British Museum (Natural History)

LICHEN GENUS MICAREA IN EUROPE 123
Habitat and distribution: In the British Isles M. cinerea is mostly found in communities of (or
closely akin to) the Parmelietum laevigatae on the trunks or over bryophytes thereon of Quercus,
Betula and, less often, Alnus, Corylus, Fraxinus, Ilex, Sorbus, Larix, Pinus, and Pseudotsuga.
Associated species in these communities include Catillaria pulverea, Cladonia coniocraea, C.
macilenta, C. squamosa, Haematomma caesium, H. elatinum, Lecidea icmalea, Lepraria incana,
Micarea alabastrites, M. stipitata, M. synotheoides, Mycoblastus sterilis, Parmelia laevigata, P.
saxatilis, Platismatia glauca, Stenocybe septata, Thelotrema lepadinum, Trapelia corticola ined. ,
Frullania tamarisci, Lejeunea ulicina, Scapania gracilis, Dicranum fuscescens, and Hypnum
cupressiforme. Less commonly it is found in the Ugnum of fallen, decorticated trunks. Occurrences
on other substrata are rare although I have found it on one occasion growing directly on
rock (Coed Hafod in Denbigh) where it was associated with Trapelia involuta on the top of a
dry-stone wall in an oak-birch wood. In addition, it was found on mosses on epidiorite at an
altitude of 1000 m in the Ben Alder range of Inverness-shire by Dr O. L. Gilbert; the specimen is
sterile but has pycnidia with the characteristic macroconidia. In Britain M. cinerea usually occurs
at lower altitudes (mostly below 300 m), and exhibits a distribution pattern attributable to the
General Western Group of Coppins (1976). However, there are two outlying easterly localities
(in North Northumberland and East Perth) both of which are sheltered, more or less undisturbed,
valley woodlands.
From outside Britain I have seen material of M. cinerea from Hordaland and Rogaland in
western Norway, the east Sudety and Vysoke Tatry of Czechoslovakia, southern Germany, and
the Swiss, Austrian and Italian Alps. Most collections from southern Germany and the Alps are
Map 6 Micarea cinerea • 1950 onwards O Before 1950