COMMON HEMP-NETTLE (Galeopsis tetrahit)
In my seventh season of botanising, I came across a
single plant of this species by a waste plot in Dagenham. A
few days later, a procession of the Hemp-nettle was found
bordering a cornfield in the Theydon parishes, and a fine
bank of 100 cm. plants against a wall at Hobbs Cross in the
same vicinity. Once known, this rough, hairy plant is
readily recognised, but its appearance varies according to
habitat and its distribution in Essex, though generous
enough, seems somewhat sporadic.
The flower colouring can vary a good deal, being most
generally pink or purple. The pink variety is more
attractive and both can be found together where the colony
is fairly large. On the chalk downs overlooking Folkestone
I have seen large numbers of small plants all bearing a
flower of quite distinctive pattern in cream and mauve. In
some places the plant behaves coyly, and on the edge of a
Dartmoor common it was only recognisable by the flowers
hardly overtopping grasses beneath a hawthorn. Within our
county I have also seen the white or near-white variety with
a network of pink or purple veins on the lower lip.
The most surprising find was under a shrub in my garden
where, for two seasons a fine bushy plant with many small
pale flowers was assumed to be a respectable garden species
of Scrophulariaceae. When my wife disowned it as one of my
weed importations, I looked more closely. To my surprise it
turned out to be a clump of several Galeopsis tetrahit with
pale—veined flowers of a variety I have never seen elsewhere.
It can only be assumed that the secret of its appearance lay
in the birdseed put out nearby.
This is a species worth looking out for, not too common
to be taken for granted, but bearing variations of form and
colour worthy of record, I cannot yet claim to have seen
the variety specified in C.T.W., "...rarely yellow with violet
lower lip".
Eric N. Hooper
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