In much of its range, this cushion-forming moss seeks out very sheltered places, such as crevices below and between boulders and recesses in rock faces. It’s often restricted to the north-facing side of a feature, where the risk of desiccation is lowest. In areas of particularly high rainfall, it may also grow out in the open on old walls or rock exposures, but only where they are relatively sheltered too.
C. bruntonii varies in size, typically forming cushions of about the same size as Dicranoweisia cirrata, which prefers more exposed places. You’ll generally need capsules for certain identification – when dry and mature, they are smooth. The leaves are long and whippy-looking and resemble those of many other species until you get them under a microscope. Then you’ll see low but distinct marginal teeth in the upper part of the leaf. The upper leaf lamina is partially bistratose, making it look opaque. However, this character – and the remarkable conical mamillae projecting from the leaf cells – is most easily seen if the leaves are sectioned transversely. Close examination of the rhizoids under high power often also reveals elongate rhizoidal gemmae. There are some images below showing these important characters.Read the Field Guide account