A botanical conundrum
Graham Smith 48 The Meads, Ingatestone, Essex CM4 OAE
You would expect, wouldn't you, that if you dug a hole and then filled it in again, using the
same soil, the bare earth would eventually be colonised by much the same plant species as
were there previously. For the first year or two, though, opportunistic annual weeds would
grab their chance to flower and set seed. From an amateur botanist's point of view these
two years are the most interesting part of the process. Thus, I am always on the look out for
any road works or pipe laying that involves clearance of the existing vegetation from
roadside verges. During the winters of 2002/03 and 2003/04 new gas mains were laid in
the Ingatestone area at Beggar Hill and on the Heybridge estate respectively. The following
springs I was there with my notebook, expecting to find a goodly array of arable weeds
and other colonists. Neither site disappointed me. At Beggar Hill the pioneers included
expected species such as Fat Hen Chenopodium album, Many-seeded Goosefoot C.
polyspermum, Spear-leaved Orache Atriplex patula, Wild Radish Raphanus
raphanistrum, Annual Mercury Mercurialis annua and - inevitably - hordes of Opium
Poppy Papaver somniferum. Among biennials, Weld Reseda luteola is a frequent colonist
of such sites while Hemlock Conium maculatum - which in my youth seemed to be
confined to riverbanks - now seems to grow almost anywhere. As for the perennial Goat's
Rue Galega officinalis, having marched along our motorways it is now spreading out
along the minor roads. Given that the site is close to houses, the appearance of Californian
Poppy Eschscholzia californica and Eastern Gladiolus Gladiolus communis also have
a logical explanation. As for Fodder Vetch Vicia villosa, it first arrived in the area a few
years ago as a grass seed contaminant on the banks of a nearby fishing lake. The big
mystery, though, was the Bastard Cabbage Rapistrum rugosum ssp. linnaeanum - over
one hundred and fifty of them! I had only found a single plant in the parish before and that
was on a roadside verge over a mile away.
At the Heybridge site the expected newcomers included arable weeds such as Fig-leaved
Goosefoot Chenopodium ficifolium, Scented Mayweed Matricaria recuitita and
Redshank Persicaria maculosa but the principal colonist was Black Mustard Brassica
nigra, the two hundred and fifty or so plants making a fine show until the local Council
mowed them! This is a species that until a few years ago I always associated with the
coast. Like so many coastal plants, though, it began appearing on the banks of the A12
- in this instance a decade ago - since when it has turned up with increasing frequency on
waste ground and verges. It remains relatively scarce in the area, however, only one or
two plants being involved in most instances.
Thus, the conundrum is this : how can you dig a hole, fill it in again with the same soil
and then find - six months later - that the bare earth has been colonised by large numbers
of two species that were not there previously and which are scarce in the area as a
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Essex Field Club Newsletter No. 46, January 2005