38
Thurrock's motorway verges.
A cliff-top promontory, that has been
cleared of scrub, now makes an attractive
vantage point over the Quarry. Here
Pyramidal and Man Orchids are again in
good numbers, with Adderstongue (Ophio-
glossum vulgatum) visible earlier in the
year. A large specimen of Purging Buckthorn
(Rhamnus catharticus), one of several
discovered only recently as a result of
management work, grows at the edge of the
cliff at this point. The warden, Graham
Starr, had previously been intrigued at the
frequency of brimstone butterflies on the
reserve, with no apparent larval food source.
Green hairstreak, too, are quite common,
although on this occasion only speckled wood,
a couple of common blues and meadow brown
were seen.
Access to the floor of the Quarry has been
greatly improved by the cutting of a gully
and construction of steps, through the
sandy infill at the north-west corner.
Fern Grass (Catapodium rigidum) was sprouting
in tufts from niches in the steps, and the
alien Great Brome (Bromus diandrum Roth. )
grows nearby. Quaking Grass (Briza media)
seems only to occur along the most open paths
of the Quarry floor, and then not abundantly.
By contrast, Wood False-Brome (Brachypodium
sylvaticum) is becoming dominant in many
places .
The reappearance, after several years, of
Common Broomrape (Orobanche minor) was a nice
surprise. Prior to the development, it had
been common in the southern half of the Quarry,
along with an interesting bright yellow var-
iant, but was rarely seen in the S.S.S.I.