104
THE ESSEX NATURALIST
Mycetozoa in Epping Forest
in 1951-52
BY JOSEPH ROSS
A matter of congratulation in regard to the recording of Mycetozoa
in Epping Forest in the twelve months ended '29 February, 1952, was
the highly successful collecting at the Club's Fungus Foray on 14 October,
when 36 species were found, this equalling the record set up at the Foray
in 1922. On the day of the 1951 Foray, 33 species were exhibited; it was
learned later that Badhamia utricularis (Bulliard) Berkeley had been seen
in the stage of plasmodium, and two somewhat weathered specimens were
proved by microscopical examination to be additions to the list. A full
list of the species was appended to the report of the Foray. (See Part 1,
p.60.)
Mr. H. Hawkins, the local meteorologist, recorded a rainfall at Chingford
of 33.7 inches for the calendar year 1951; this was much above the average.
The heaviest falls were in February, August and November. Conditions
were favourable for the development of Mycetozoa in much of the year. By
the end of September 42 species had been recorded, in October ten were
added, and November gave a further eight. The rains of November washed
immature developments away, and afterwards conditions were adverse, and
hunting in cold weather was unsuccessful. Only two more species were
found, the total for the twelve months to 29 February being 62.
It is with some satisfaction I record the finding of six species of the
genus Diderma; these were D. montanum Meylan, I). effusum (Schweinitz)
Morgan, D. spumarioides Fries. D. deplanatum Fries, D. piriforme
(Bulliard) Persoon, and D. radiatum (Linne) Morgan var. umbilicatum
(Persoon) Meylan. Of these, montanum and radiatum var. umbilicatum
are much alike superficially: they have not been found every year, possibly
because the most likely habitats were not sufficiently searched. D. mon-
tanum was found several times in November and December on leaves and
twigs amongst brambles, but seems somewhat local in occurrence.
D. radiatum var. umbilicatum is more likely to be seen on stouter sticks,
broken wood and logs which have retained bark, or on shed hornbeam bark.
D. floriforme appears in somewhat similar conditions but has a habit of
occurring on hard (and apparently hopeless) pieces of decayed hornbeam.
The other three species inhabit leaves or old bracken. D. effusum is wide-
spread in the Forest, D. spumarioides has been found frequently near
the Warren, Loughton. D. deplanatum is, in my experience, the least
common of these species in the Forest.
Uncommon species listed were Badhamia foliicola Lister, Stemonitis
hyperopta Meylan and Hemitrichia leiotricha Lister.
Included in the records of the year were six species of Physarum, six of
Didymium, eight of Trichia and six of Arcyria.