This species is a large moth, being much larger than many noctuids, and there are two forms to occur in Britain. The resident form is dark, with lighter patches on the crosslines and oval mark, while the immigrant is much lighter, appearing to be dark with dense white speckling.
The resident species is classed as Nationally Scarce B in Britain, restricted to the highlands of Scotland, while the immigrants are quite rare in the UK, but can occur anywhere in Britain. Only one record from the Channel Islands. The resident is found by moors, bogs and woodland.
The larvae mainly feed on Bog-myrtle, as well as other plants.