Ononis spinosa is a plant belonging to the family Fabaceae, that is commonly known as spiny restharrow or just restharrow. It is found throughout much of Europe including Britain, but seldom as far north as Scotland.
Prefers a sunny position in a well-drained neutral to alkaline soil. Succeeds in poor soils, the plant often becoming spiny in such a situation. Similar to O. repens but this species is not rhizomatous.
Mature roots are very tough and the plant gained its common name of 'Rest Harrow' because ploughs and harrows would be unable to break through it (in the days before heavy machinery was used on the land!). The whole plant is pleasantly scented when bruised. This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby
This plant is useful.
How to get rid of: