P. affine has trailing, non-fertile stems (shoots grow up to 10 cm long), and leaves (5 to 7 mm long) that run down onto the stem, and are toothed throughout. The leaf cells are longer than wide, arranged in diagonal rows which can be discerned with a ×20 hand lens. Capsules are very rare.

The habitat helps to distinguish P. affine from some similar Plagiomnium species which generally grow in wetter habitats.

Occurs on the ground in moist, but not wet, base-rich or slightly acidic habitats in woodland and in turf. Frequent, mainly lowland in distribution.

All year round

Widespread and fairly frequent in England and Wales, it appears to be more scattered in Scotland.

Fairly frequent in Leicestershire and Rutland.