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THE HEPATICS OF ESSEX.
By the late ST. JOHN MARRIOTT.
AS the hepatics are even more particular in their choice
of habitat than are the mosses, it is only to be expected
that comparatively few forms are to be found in Essex, where
the elevation is usually low, rocks are scarce, transpiration
excessive and the rainfall small. Under such conditions, with
the exception of a few widely distributed Xerophytic forms,
these cryptogams are confined chiefly to either woodlands or other
sheltered situations, or to bogs, ponds, or marshland, so that
the area in which they can be sought for successfully is restricted.
Moreover, extensive building operations, destruction of woodland,
drainage and cultivation, have partially spoiled, or ruined
many of the old habitats, so that this area is probably con-
siderably less now than it was in the times of E. Forster and
E. G. Varenne. Nevertheless, it seems unlikely that the de-
crease in suitable habitats is the sole reason for so large a pro-
portion as fourteen, out of a total of fifty-one species recorded
for the county, not having been observed during recent years.
It seems more reasonable to suppose that if the county was
worked more thoroughly for hepatics, not only would many
of the old records be re-established, but a number of new species
would be added to the list. It is unfortunate that the study of
the distribution of even those forms that are known to occur in
Essex has been neglected. Practically no information of any
real value, except with regard to certain limited areas, such as
Epping Forest, is available on that head. It is in this direction,
perhaps, that the more valuable work on the hepatics of Essex
remains to be carried out.
Of the fourteen species that do not appear to have been
re-discovered in the county since the days of E. Forster or
E. G. Varenne, the majority are probably still to be found in
Essex, as all, with the exception of Saccogyna viticulosa, occur
both in Kent and in Surrey. Of the more recent records,
Ptilidium pulcherrimum, first observed in Epping Forest by
Mr. J. Ross in 1917, is remarkable, as although this species
has been noted in S. Somerset and in Derby, it is much more
frequently met with in the North, where it extends as far west