REPORT ON THE LICHENS OF EPPING FOREST. 
93 
have already remarked the almost entire absence of fruticulose 
forms, such as Evernia, Ramalina , and Usnea, which are 
common enough in other districts of the S.E. of England. 
In the Forest, perhaps the most abundant tree-dwelling lichen 
of all is Lecanora varia, which (with its doubtfully distinct 
relative, L. conizceoides ) is universally met with clothing the 
trunks and branches of trees ; in open situations, such as about 
“ Black Bushes,” N. of Earls’ Path, Loughton, and elsewhere, 
the stems and branches of small hawthorn bushes are frequently 
entirely covered with this lichen, in full fruit, giving the bushes 
a characteristic, hoary grey-green appearance, from which 
only the smaller and younger twigs are exempt. These smaller 
twigs show, too, that the lichen starts from definite centres, 
where spores have germinated, whence, spreading as circular 
patches, these at length coalesce and clothe the entire bush 
with a dense tomentose fur ; occasionally, another lichen, Par- 
melia physodes, form labrosa, grows with Lecanora on the 
older branches of the hawthorn. Bushes of Sallow, small Crab 
and Oak trees, and the stems of Gorse and heather are so covered, 
and the same two species of lichens are often seen associated 
together on old Birch trunks, especially the rough, corky portion 
near the butt. 
On bare trunks of Hornbeam, where free from ' Chlorococcus, 
many of the less conspicuous crustaceous lichens find their 
habitat, the more characteristic forms being Lecanora rugosa, 
sub-sp. chlarona, Pertusaria wulfenii, Lecidea griffithii (this 
species is extremely abundant in a spermogoniferous condition), 
Enterographa crassa, Opegraphas and Graphis of various species, 
and Acrocordia gemmata. 
On decaying tree-trunks, Lecidea granulosa sometimes occurs 
m great profusion, although its more usual habitat is,as already 
stated, on bare heathy ground. 
On the cut ends of stumps and on decorticated timber, 
Parmelia fuliginosa and Lecidea flexuosa are often met 
with. 
Old brick walls, on their northern faces especially, yield 
Lecanora galactina, L. exigua, Buellia canescens, Lecidea lucida, 
and Urceolaria scruposa, among other forms ; while Lecanora 
saxicola prefers the upper surface of the wall-top. The cement 
joints and rendering of the walls are the favourite stations of 
H 
