The Moss Families of the British Isles


L. Watson and M. J. Dallwitz


Gametophyte. Acrocarpous; forming patches (these glaucous green above, and reddish brown below). Shoots complanate. The leaves ovate to lanceolate, or lanceolate; on sterile stems, distichous (with their bases confluent, the fertile stems similar but with smaller leaves, or the latter confined to apical rosettes). Leaf bases decurrent (and confluent on sterile stems). The leaves nerveless. Leaf blade apices pointed; apically acute to acuminate. Leaf blade margins entire. Leaf blades not conspicuously bordered. The basal leaf cells longitudinally much elongated; rhomboidal; smooth. The walls of basal leaf cells thin; straight. The mid-leaf cells longitudinally much elongated; hexagonal, or rhomboidal; smooth. The walls of the mid-leaf cells thin; straight.

Plants (pseudo-) dioecious (the separate male and female plants arising from the same protonema).

Sporophyte. Capsules exserted; erect; symmetrical; globose, or ovoid; without an externally conspicuous apophysis; without a peristome. The operculum convex. Setae to 4 mm long, slender; straight.

Ecology. Occurring in acid conditions. In acidic, friable soil on shaded banks, cave entrances, rabbit warrens, etc., especialy in sandstone areas.

Cytology. Haploid chromosome number, n = 11 and 14.

British representation. 1 species. Schistostega (Luminous Moss). Northern Scotland, southern Scotland, northern England, English Midlands, East Anglia, Wales, southeast England, central southern England, southwest England, and Isle of Wight (occurring widely, but sporadic in England and Wales, very rare in Scotland, and seemingly absent from Ireland).

Classification. Class Bryopsida; Subclass Dicranideae; Order Dicranales.

Comments. Stems of two forms: barren, with distichous leaves having confluent bases, and fertile, these either with similar but smaller leaves, or with only terminal tufts or rosettes of smaller leaves. The light-refractive protonemata give an impression of luminescence when the plants are viewed in dark places.

Illustrations. • Schistostega pennata. Schistostega pennata. • Schistostega, with Oedipodium: Berkeley.

To view the illustrations with detailed captions, go to the interactive key. This also offers full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa.

Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2005 onwards. The moss families of the British Isles. Version: 21st June 2009.’.