Field Pepperweed (Lepidium campestre), fam. Brassicaceae.
Found as a weed along the railways. These plants are quite elegant, topped with heads of dirty-white flowers, blooming in May.
The plant has antibacterial properties. The decoction of its seeds is used externally as compresses for rheumatism, and internally as carminative and antiscorbutic.
A related species – Garden Cress (Lepidium sativum) – is grown sometimes as a vegetable. Another species – Narrowleaf Pepperwort, or Roadside Pepperweed (Lepidium ruderale) – contains phytoncides and toxins in greater concentrations, so it is used as bug repellent; here the Russian name of the plant originates, meaning the "plant against bed bugs".