The Moss Families of the British Isles


L. Watson and M. J. Dallwitz


Gametophyte. Pleurocarpous (Tetraplodon, Tayloria), or acrocarpous (Splachnum); forming tufts, or forming patches, or growing through other Bryophytes. Mature plants 10–70 mm high. The leaves soft, elliptical to oblong, or ovate to linear, or lingulate, or spathulate to obovate; spiral; single-nerved. The leaf nerves extending beyond the middle of the leaf, but not to the tip, or extending to the leaf tip; not excurrent. Leaf blade apices obtuse, or pointed; apically rounded to apically acute, or acuminate. Leaf blade margins flat; entire to dentate. The basal leaf cells somewhat longitudinally elongated, or longitudinally much elongated; rectangular to hexagonal; smooth. The walls of basal leaf cells thin; straight. The angular cells not well differentiated. The mid-leaf cells somewhat longitudinally elongated to longitudinally much elongated; rectangular, or hexagonal, or rectangular to hexagonal, or rhomboidal; smooth. The walls of the mid-leaf cells thin; straight.

Plants monoecious, or dioecious; when monoecious, autoecious.

Sporophyte. Capsules exserted; erect; symmetrical; straight; sub-cylindric, or ellipsoid, or pyriform (sometimes waisted, in Splachnum sometimes panduriform or inverted mushroom-shaped); with an externally conspicuous apophysis (similarly shaped to the theca, or much enlarged). The apophysis becoming conspicuously rugose and/or twisted (pyriform, globose or umbrella-shaped). Capsules above the apophysis, smooth. Calyptra symmetrical; splitting down one side, or with two or more splits, or tearing irregularly, or entire. Capsules with a peristome. The peristome single. The peristome teeth 16; not grouped, or in pairs, or in fours; not deeply cleft; not perforated; thin, membranous, and transversely barred; exteriorly with a fine longitudinal dividing line between the transverse bars. The operculum conical to mamillate. Setae long; straight, or flexuose.

Ecology. Nitrophilous. Almost aways growing on excrement or decaying animal or plant matter, and the spores often dispersed by fies.

Cytology. Haploid chromosome number, n = 8, 10, 11, and 19 (Tetraplodon), or 9 (Splachnum).

British representation. 8 species. Aplodon (Carrion-moss), iSplachnum (Collar-mosses), Tayloria (Gland-mosses), Tetraplodon (Cruet-mosses). Northern Scotland, southern Scotland, northern England, English Midlands, East Anglia, Wales, southeast England, central southern England, southwest England, and Ireland (but mostly northern).

Classification. Class Bryopsida; Subclass Bryideae; Order Splachnales.

Illustrations. • Splachnum ampullaceum, S. sphaericum and S. vasculosum: Dixon. • Aplodon, Tayloria, Tetraplodon: Dixon. • Tayloria lingulata and T. tenuis: Berkeley. • Splachnum and Tetraplodon: Berkeley. • Splachnum ampullaceum: Curtis (1830).

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.’.