Wingspan 30 to 40 mm. Distinguished from similar species by the broad rounded forewing, it is a species where expert help with identification is recommended.

Occupying deciduous and coniferous woodland.

The adults fly in a single generation from June to August, and can be attracted to light.

The dark brownish caterpillars feed on a variety of coniferous trees, including Yew and Spruce.

This species is distributed mainly in the southern half of England and Wales, with a few scattered colonies northwards to Scotland. In a recent survey to determine the status of all macro moths in Britain this species was classified as common.

It appears to be uncommon in Leicestershire and Rutland, where there are few records, but this may be partly due to the difficulty of identification. L&R Moth Group status = D (rare or rarely recorded)