REPORT ON THE LICHENS OF EPPING FOREST.
proof of vitality and power to colonise new areas, we may
mention that in a garden at Theydon some dozen small
individuals of Parmelia physodes and P. exasperata have made
their appearance during the present winter (1909-10) on an oak
log, which last summer showed no recognisable traces of lichens.
Some very healthy specimens occur on the great horizontal
beech roots which are uncovered by soil for some distance
from the trunks. These plants have some advantages over those
growing directly on the trunks: i.e., they get more light, more
moisture when it falls, and they are exceedingly well drained.
So far, the Graphidei have been difficult to identify and, for
the present, several remain undetermined, owing to absence of
spores in those collected. We do not conclude from this that
the genera Graphis and Opegrapha are declining, for apothecia
are abundant and healthy-looking. It may be that the specimens
were not gathered at the most favourable time for spores.
The scarcity of old brick walls and tiled roofs in the district,
or their too careful repair (from a lichen hunter's point of view),
and the entire absence of hard rocks, militate against the
frequent occurrence of the saxicolous forms, but Xanthoria
parietina, Lecanora vitellina, and Lecanora galactina are met with
on walls and tombstones. Lecidea petroea is not uncommon on
old flint pebbles embedded in some of the Forest paths.
Within the last 12 months we have collected and identified
42 of the lichens known to be extant 27 years ago. To these we
have added two then believed to be extinct, and two which were
not included in the list so often referred to.*
In conclusion, we wish to acknowledge very gratefully the
valuable assistance rendered to us by Miss Lorrain Smith and
Mr. E. M. Holmes, F.L.S., in naming some of the specimens
collected.
The present list of the lichens of the Forest is as follows :—
Family—LICHENACEI.
Tribe—CALICIEI.
Calicium curtum, Turn. and Borr.
On rotting stump between Epping New Road and
Woodreddon Hill; fertile.
* This total has been very considerably increased in the interval that has elapsed since
the paper was read and we propose to publish an additional list in due course.