7
the chalky-boulder-clay flora has been all
but exterminated in Essex by several decades
of flail-mowing and a decade of road widening
and rotted tarmac dumping. Only two patches
of Rockrose are now known in these areas
today, as against at least twenty-five in
the 1960's, and the Clustered Bellflower,
Marjoram, Stemless Thistle and Pyramidal
Orchid are now extinct - although they still
occur on pure chalk verges further north, and
the Pyramidal Orchid occurs as a sporadic
initial colonist on newly exposed type (ii)
sites.
(ii) The second type of chalky-boulder-clay
flora occurs on the (presumably) somewhat
less chalky-boulder-clays of the majority of
north-west Essex, where, however, the chalky-
boulder-clay forms a continuous deep blanket
over the landscape. Here the indicator
species of type (i) are absent, except for
the Pyramidal Orchid, which, however, is
merely an occasional initial colonist on
this type of boulder clay, readily crowded
out as soon as a sward develops. Other
early colonists such as the Bee Orchid,
Blue Fleabane, Grass Vetchling, Scabious,
Cowslip, Yellow-wort, Centuary, Sulphur
Clover and Quaking Grass vary in their per-
sistence. During the 1960's, when C class
roads of the north-west of the county were
upgraded to take heavier, faster and more
frequent traffic, the high banks on numerous
bends were shouldered, overhanging banks were
lowered and really bad bends were bypassed.
In those days the resulting verge surfaces
were left as pristine, unweathered chalky-
boulder-clay, not gravelled or top-soiled as
such surfaces are today. First on the
ground, the Knotgrass, Scabious and Bee Orchid,