The Moss Families of the British Isles


L. Watson and M. J. Dallwitz



Gametophyte. Pleurocarpous (?), or cladocarpous; straggling, forming tufts. Primary stems long and irregularly branched. Mature plants sometimes with shoots to as long as 150 cm. The branches in fascicles (sometimes), or not in fascicles. The leaves of main stems and branches similar in form; ovate to lanceolate, or orbicular to ovate; often more or less 3-ranked; nerveless. Leaf blade apices pointed; apically acute. Leaf blade margins flat; entire. The basal leaf cells longitudinally much elongated (narrow); hexagonal, or rhomboidal, or linear; smooth. The walls of basal leaf cells thin; straight. The angular cells clearly differentiated (usually enlarged and forming distinct auricles). The mid-leaf cells mostly narrowly longitudinally much elongated; hexagonal, or rhomboidal, or linear, or linear to vermicular; smooth. The walls of the mid-leaf cells thin; straight.

Sporophyte. Capsules immersed (on rather elongated perichaetial branches), or emergent to exserted, or exserted; erect, or inclined; symmetrical; straight; sub-cylindric to ovoid; without an externally conspicuous apophysis. Calyptra symmetrical; minute, smooth. Capsules with a peristome. The peristome double. The peristome teeth 16 (red); not deeply cleft; not perforated, or perforated; thin, membranous, and transversely barred; exteriorly with a fine longitudinal dividing line between the transverse bars. The inner peristome about equalling the outer; with elongated “processes” (these filiform, and united into a cone via transverse bars); ciliate (as usually interpreted, but the cilia united with the processes). The cilia and processes of the endostome united by transverse strands into a conical lattice. The operculum rostellate, or rostrate. Setae present to absent (the capsule more more less sessile or subsessile); if present, very short; straight.

Ecology. Often amphibious, aquatic and in wet places. Variously in fast-flowing water, on rocks or tree bases subject to submergence, in seepage areas, etc.

Cytology. Haploid chromosome number, n = 10 and 11 (only F. squamosa sampled).

British representation. 2 species (each with several varieties long treated as distinct species). Fontinalis. Northern Scotland, southern Scotland, northern England, English Midlands, East Anglia, Wales, southeast England, central southern England, southwest England, Isle of Wight, and Ireland.

Classification. Class Bryopsida; Subclass Bryideae; Order Hypnales.

Illustrations. • Fontinalis antipyretica, F. dalecarlica, F. seriata and F. squamosa: Dixon. • Fontinalaceae, Cryphaeaeae, Hookeriaceae, etc.: 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.’.