Common Hemp-nettle
When feed for livestock is in short supply, hedgerows and vegetation growing between shrubs provides a useful alternative source of nourishment. But since clover is not always readily available, an emergency diet will obviously include some unwelcome plants.
One of these is Common Hemp-nettle. True, its seeds are quite large and contain a fair amount of fatty substances, but they are also relatively toxic. Feed containing as little as five per cent Common Hemp-nettle causes poisoning of livestock, particularly horses, in which it induces a kind of depression or melancholia.
The generic name Anagallis is derived from the Greek word Anagelae, meaning to make one laugh, and the Scarlet Pimpernel certainly looks merry enough.
It is most likely to be damaged by the presence of even a slight spring or autumn frost. Common Hemp-nettle used to be an annoying weed in field crops, particularly grain, when these were harvested by hand as the spiny points of the calyx after flowering caused painful scratches. However the plant yields a drug used to treat diseases of the respiratory tract.
The Scarlet Pimpernel is a very hardy and undemanding plant. In a congenial site, particularly in warm regions, it flowers throughout the summer, from June until October. The fruits are capsules which release seeds through a circular opening capped by a lid.
A single plant produces as many as 700 seeds. The Scarlet Pimpernel is an annual herb but in mild winters it may survive and commence growth again in spring. Since it does not have a deep root system, winter does not pose as much of a threat as summer drought. It is a weed of field crops – root or grain.
