When encountered, often on rocks near fast-flowing northern and western watercourses, S. apocarpum looks ‘different’. Its reddish stem colour is often prominent and its stems often curve in one direction. An important character is the hair-point, which is frequently so short as to appear to be absent. However, it is a highly variable moss and strongly coloured forms with papillae on the back of the nerve may fool even seasoned bryologists into thinking they have found S. strictum, an uncommon moss of the uplands. Unlike that species, however, S. apocarpum always has smooth upper laminal cells. And it can also be reliably distinguished from S. crassipilum by its predominantly isodiametric and transversely widened capsule exothecial cells and larger spores.
Many bryologists consider the key in Elsa Nyholm’s Illustrated Flora of Nordic Mosses to be one of the best currently available for the British and Irish species.Read the Field Guide account