94 REPORT ON THE LICHENS OF EPPING FOREST.
Lecanoras vitellina, murorum, and galactina, and Verrucaria
nigrescens.
Tombstones in old churchyards present a quite characteristic
assemblage of lichens, including Physcia pulverulenta sub-sp.
pityrea, P. stellaris sub-sp. tenclla, P. parietina, form congranulata,
Lecanora murorum, L. subfusca, var. campestris, and Buellia
canescens.
Old leather will afford a rest-place for various lichens if
sufficiently soddened ; we have noted Cladonia fimbriata, var.
tubaeformis and Lecidea granulosa growing on an old boot in the
Forest : and we have even seen tiny fruiting individuals of
Cladonia macilenta and C. fimbriata, var. tubaeformis growing on
the dry clung of rabbits.
ASPECT.
All lichens love the light, but there is a considerable difference
in the intensity of the light which various species prefer. The
yellow-coloured forms appear to revel in full sunlight, the flaves-
cent Physcias and Placodia being striking instances. Thus,
Physcia parietina, form congranulata, prefers the south faces
of walls, where the surface of the stone or brick becomes un-
bearably hot to the touch in the full glare of the summer sun ;
and the form cinerascens of the same species occurs chiefly on
the south side of beech trunks in the Forest. Lecanora mur-
orum is more frequent on sunny walls and tombstones, and
L. vitellina affects the south faces of walls. In contrast with
these, the green-hued Parmelias are very frequently found in
the Forest on the north and west sides of tree-trunks.
FRUITING SEASON.
There would seem to be few records as to the season of the
year when lichens are accustomed to produce their apothecia
in this country. Our own fragmentary notes in this connection
must be regarded as merely tentative, pending the accumulation
of further observations, but so far as they go, they undoubtedly
tend to show that the fruiting period for these plants is the
winter months, extending from the beginning of November
to the end of April. Thus, taking Baeomyces rufus as a type of
many others, we have noted it with small apothecia on September
9th and 19th, with well-formed apothecia on November 26th,