Roof Moss

Barry’s moss roof post reminded me of an unusual roof moss I noticed amongst some of my old photographs recently.  Back in 2004 when Sam and I were doing some recording for the Carmarthenshire bryophyte flora we spotted some tufts of Campylopus atrovirens growing on a slate roof. 

The roof in the photograph is near Allt Rhyd y Groes National Nature Reserve in the very north-east of Carmarthenshire - one of my most favourite parts of Wales.    This oceanic species has a very western distribution in Britain, and in south Wales I think I have mostly seen it growing in wet heath, especially where there is some slight flushing – in the Allt Rhyd y Groes area it probably rains more days than it doesn’t, so probably not surprising a moss like this can grow in such an exposed spot.
  
I think the only other Campylopus species I have seen on roofs is C. introflexus – fairly common on thatch but also sometimes growing between roof tiles, where it takes on a very distinctive growth form of tall, very straight-sided tufts, easily identified as this species from a good distance away.