Identification notes
In most areas, this is a much scarcer moss than O. anomalum, which it sometimes grows with. In drier parts of the country, O. cupulatum seeks out more humid and sheltered niches than O. anomalum. Look for it for example low down on the sides of church tombstones and memorials. O. anomalum is more likely on wall-tops and exposed places, except in high rainfall areas where both are possible out in the open.
It’s an easy species to recognise in spring, when its capsules are well-developed and plump-looking (another point of difference from O. anomalum).
In Yorkshire, Brecknock and certain other limestone area O. cupulatum forma riparium can be found on rocks in fast-flowing watercourses (see image below). In that habitat, with its blackish colour and exserted capsules it looks more like O. rivulare than O. cupulatum. Elsewhere, var. riparium has been recognised as a distinct taxon. It is not even currently recognised as a variety in Britain and Ireland but it is nonetheless an attractive and charismatic little moss.
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