About Ononis arvensis L.
Ononis arvensis, commonly known as field restharrow, is a widespread flowering plant species in the legume family Fabaceae. It is native to Eurasia, ranging from central Europe through western Siberia to the western Himalayas. It is a perennial hemicryptophyte that typically grows 50–100 cm (20–39 in) tall. It is most often found in meadows, and also occurs in old fields and dry grasslands. It is closely related to Ononis spinosa and Ononis repens; some authors treat Ononis arvensis, along with O. repens, as a subspecies of O. spinosa. It shares pink flower colour with both of these related species. Compared to O. spinosa, it differs by bearing its flowers in pairs at each node instead of singly, and like O. repens, it lacks stiff spines. Like O. spinosa, its wing petals are small, instead of being equal in length to the keel petal as seen in O. repens. It has a more easterly distribution than either O. spinosa or O. repens: it is not found west of southern Scandinavia and Germany, and it extends further into central Asia.
