Wingspan 17-23 mm.
This moth is distributed widely over much of Britain and Ireland, and, since the 1990s, has become much more frequent, including in gardens.
Like its relative, A. punctidactyla, the hindwing has two patches of black scales on its dorsum, which protrude when the rest of the hindwing is covered by the forewing. Amblyptilia acanthadactyla may be distinguished by its warm reddish brown colour from the greyish brown of A. punctidactyla.
There are two generations, with moths on the wing in July and again from September onwards, flying after hibernation until May. The adults are attracted to light.
The larvae feed in June and in August on the flowers and young leaves of a large range of plants, including restharrow (Ononis spp.), Hedge woundwort (Stachys sylvatica), cranesbills and cultivated geraniums (Geranium spp.), goosefoots (Chenopodium spp.), heathers (Calluna and Erica spp.), and mints (Mentha spp.) On the continent, it has also been reported on Salvia, Teucrium scorodonia, Lavandula, Euphrasia, Carlina, Vaccinium, Calamintha and Nepeta. Several other plume species feed on some of these plants, so caution should be exercised when identifying the larvae.