Wingspan 29 to 37 mm. Although varying in degrees of contrast, this is normally a dark brown species, as the English name suggests. The trailing edges of the wings are distinctly scalloped.

Usually associated with calcareous soils.

July and August.

The caterpillar has two forms - one pale green; the other dark brown and cream. The foodplant is Buckthorn.

The species is found in England and Wales, being commoner in the south. In a recent survey to determine the status of all macro moths in Britain this species was classified as local.

Fairly frequent but not common in Leicestershire and Rutland. L&R Moth Group status = B (scarce resident or restricted distribution or regular migrant).