BIRCH GROVES OF EPPING FOREST. 77
(2) at High Beach, within the churchyard, circumference 83"
(3) „ Long Running „ 56"
(4) „ Genesis Slade „ 46"
(5) Epping Thicks „ 47"
Number (5) was blown down during a storm of the early spring
(1922). Mr. Gerald Buxton, Verderer of the Forest, kindly pro-
vided a transverse section of the trunk for the Club's Museum,
from which the following measurements were taken :
Greatest diameter 15.5"
Width of widest annual ring, .3"
Radius from centre to :—
Outside of 5th annual ring 1.125"
10th „ ,, 2.5
15th „ „ 3.0
20th „ „ 4.0
25th „ „ 5.375
35th „ „ 5.75
This tree was 38 to 40 years old when blown down.
There appears to be a tendency for birches to grow in defi-
nite groups of two or three trees. At High Beach the following
occur :—
(1) A group of 3. Circumferences 24", 19", 18" respectively.
(2) „ „ 3 ,, 16", 14", 13.5"
(3) ,, ,, 2 ,, 20.5", 16"
(4) ,, ,, 2 „ 24", 20"
(5) ,, ,, 2 „ 10.5", 11"
Some apparent groups are due to injury to the young tree
when two to three stems arise just above the ground.
It may be that the small group represents the survivors of a
larger number of seeds that germinated. It has already been
pointed out how large a number of these fall in the autumn
upon one square inch of soil.
To discuss the lack of agreement among the standard floras
respecting the nomenclature of the genus Betula, is beyond
the scope of this paper. Suffice it to say that, for the purpose
of avoiding confusion, the system followed is that of the Cam-
bridge Flora, which divided British birches into two series (1)
the Albae, (2) The Nanae. The first series includes two species,
Betula alba, L., commonly known as the white birch, and B.
pubescens, the common birch; both of which, with varieties
and probably hybrids, occur in the Forest.