Flora and fauna: Tenacious plant with therapeutic benefits
Restharrow (Ononis repens)
RESTHARROW is an attractive, compact, mat-forming plant with small sweetpea-shaped flowers which appear in abundance between May and September.
The stems are somewhat hairy, and the small oval leaves have toothed edges.
The Latin name Ónonis comes from the Greek word for donkey, as the plant was known to have been used as food for these beasts.
In fact, the stems are so wiry and spiny that no other animal would consider them as food.
The English name of restharrow refers to these tough, woody roots because they are so strong and tenacious that they proved capable of stopping in their tracks harrows being pulled by even the strongest of horses.
The word repens, on the other hand, means “creeping”, and refers to the spreading nature of the plant.
The pretty but unscented flowers range from pink to purple and appear in profusion throughout the summer. They benefit from a specialised type of pollination called piston mechanism.
When a bee lands on the lip of the flower it forces the heads of the pollen-bearing stamens together, squeezing out a ribbon of pollen.
Since the plant thereby self-pollinates, it is referred to as hermaphroditic.
There is a moth (Aplasta ononaria) that shares not only its specific name, onoraria with the plant, but also its English name of Restharrow, presumably because it lays its eggs there.
It was familiar to the ancients. It was first described by Theophrastus in the first century AD, and Dioscorides and Galen both mentioned it for its medicinal properties.
Its therapeutic value lies in these troublesome roots. Shavings of them prepared in wine were known both to increase urine flow (in horses as well as in humans) and to destroy and expel kidney stones.
Lonicerus of Marburg (c. 1545), wrote that “this excellent herb flushes out stones and urine in man and animals, which is why it is also called stone-root”.
Restharro’'s roots, soaked, make a drink tasting similar to liquorice, to which the plant is in any case related, and shoots have historically been boiled as a vegetable, or used in salads.
Restharrow can be found near the Green Bridge, in Barnard Castle, but it is doubtful whether those who like to dig their garden soil over with ease will come to find it in sufficient numbers to have to form an orderly queue.
Dr Richard Warren is a botanist living in Barnard Castle