MYCETOZOA IN EPPING FOREST 35
Mycetozoa in Epping Forest in
1950-1
BY JOSEPH ROSS
The greater part of the twelve months from 1 March 1950 to 28
February 1951 was favourable for the development of Mycetozoa in
Epping Forest, and as forty-nine species had been recorded by 14 October,
the date of the Club's Fungus Foray, one had hopes of a successful year.
Disappointment, however, followed. October was a very dry month with a
rainfall of only 0.3 inch according to the statistics prepared by Mr. H. Haw-
kins, of Chingford. Before the effects of that drought had worn off, a long
chilly winter with frequent night frosts had set in, and in the four months,
November to February inclusive, only four species were added to the year's
list, making a total of fifty-three.
The rainfall of these four months is worth placing on record: November
4.39 inches, December 1.61 inches, January 2.54 inches, February 5.51 inches.
In October thirty-eight species were listed and in November thirty; in Decem-
ber, with frost and some snow, the number fell to fifteen, in January to ten
and in February to six. The rain of November and February washed away
some developments, and in the unfavourable conditions some emergences
such as Comatricha nigra (Persoon) Schroeter and Arcyria ferruginea Sauter
failed to mature, but throughout the winter when the snow and frost dis-
appeared it was a delight to find that Colloderma oculatum (Lippert) G. Lister
had been preserved by its gelatinous envelope on the old oak log it has
favoured for so many years. Mr. Hawkins reported that the rainfall of the
calendar year 1950 was 24.22 inches, which was slightly below the Chingford
average.
The outstanding feature of the year was the finding of seven or eight
developments of Trichia floriformis (Schweinitz) G. Lister at the Club's Fungus
Foray which was in the part of the Forest near Theydon. In the third edition
of the Monograph the habitat of the species is said to be "decayed wood,
especially of coniferous trees"; at the Foray it was found on logs of willow,
hornbeam, birch, and beech, and in each case the logs were much decayed and
were able to retain considerable moisture; several bore other species of
Mycetozoa. T. floriformis had been previously recorded from two stations in
the Forest: first in October 1946 on a willow log in Oak Hill, where it was
again found at the 1950 Foray, and in April 1949 on hornbeam near the drive
at Birch Hall in company with Stemonitis fusca Roth and S. ferruginea
Ehrenberg. One group of beech logs examined at the Foray besides T. flori-
formis yielded T. scabra Rostafinski, T. varia Pers., Hemitrichia Vesparium
(Batsch) Macbride and S. fusca.
The Club's spring field meeting in the Forest in 1951 was partly in the same
area as the Fungus Foray, and several groups of Trichia spp. and H. Vesparium
were found in a much weathered condition with a few recently matured
sporangia of T. floriformis on one log. From this recent experience one in-
clines to the view that T. floriformis will thrive on a variety of woods if the
logs are in suitable condition, i.e. sufficiently decayed; also that the species
may have a somewhat longer season than the closely related T. Botrytis Pers.,
although the last mentioned may rarely occur late in spring. We know that
T. floriformis has occurred on willow in four consecutive years. Early in
October 1950 Mr. H. J. Howard, of Norwich, added T. floriformis to the list