The engrailed and small engrailed are moths of the family Geometridae found from the British Isles through central and eastern Europe to the Russian Far East and Kazakhstan. The western Mediterranean and Asia Minor and the Caucasus represent the southern limit of the distribution. In the north, the distribution area ends at the Arctic Circle. It also occurs in North America. Debate exists as to whether they make up one species, or whether E. crepuscularia actually refers only to the small engrailed, with the engrailed proper being separable as E. bistortata.

Aconitum, also known as aconite, monkshood, wolfsbane, leopard's bane, devil's helmet, or blue rocket, is a genus of over 250 species of flowering plants belonging to the family Ranunculaceae. These herbaceous perennial plants are chiefly native to the mountainous parts of the Northern Hemisphere in North America, Europe, and Asia, growing in the moisture-retentive but well-draining soils of mountain meadows.