Devil's-bit Scabious

It's a flowering plant of the genus Succisa in the family Dipsacaceae. It differs from other similar species in that it has 4 lobed flowers, whereas Small Scabious and Field scabious have 5 lobes and hence it has been placed in a separate genus in the same family. It also grows on damper ground.
Its leaves are also un-lobed unlike Field scabious,and are arranged in opposite pairs. The leaves and plant can be confused with Greater Knapweed however Knapweed has leaves that are alternate, not opposite.
It prefers moist soil—damp meadows and woods, lowland heath, marshy areas; but will tolerate drier conditions. Male and female flowers are produced on different heads, the female being smaller.Flowers from June until October.
It is a good source of nectar and is the foodplant of Marsh fritillary, whose eggs are laid in groups on the underside of the plant, and Narrow-bordered Bee Hawk-moth Hemaris tityus. As both plant and invertebrates are rare, their survival relies on careful management of sites containing these species.