The Moss Families of the British Isles


L. Watson and M. J. Dallwitz




Gametophyte. Cladocarpous (the fruits forming at the extremities of short laterals). Mature plants taking the form of floating or decumbent tufts, 20–120 mm long (C. fontinaloides), or 50 mm tufts (C. riparius). The leaves bilaterally symmetrical, or markedly asymmetrical; oblong, or lanceolate to narrowly lanceolate, or lingulate; spiral; secund (when moist), or not secund; single-nerved. The leaf nerves extending to the leaf tip; slightly excurrent, or not excurrent. Leaf blades not lamellate. Leaf blade apices obtuse, or pointed; apiculate (C. apiculatus), or not apiculate; apically rounded, or apically acute; not hyaline. Leaf blade margins two- to several- stratose flat, or revolute or recurved; several-stratose (3–5 stratose, at least distally). Leaf blades bordered. The basal leaf cells more or less isodiametric to somewhat longitudinally elongated, or longitudinally much elongated; rectangular, or rounded; papillose, or smooth. The walls of basal leaf cells thin (usually), or thick; straight. The angular cells clearly differentiated, or not well differentiated. The mid-leaf cells more or less isodiametric; hexagonal to rounded, or rounded to rhomboidal; faintly or strongly papillose. The walls of the mid-leaf cells thin to thick; straight.

Plants dioecious. Plants not gemmiferous.

Sporophyte. Capsules immersed (C. fontinaloides), or exserted; erect; symmetrical; straight; sub-cylindric to ellipsoid; without an externally conspicuous apophysis; smooth. Calyptra symmetrical; splitting down one side. Capsules with a peristome. The peristome single. The peristome teeth 16; conspicuously spirally twisted, or not spirally twisted; joined basally to form a membranous ring (or the teeth more or less latticed below, with connecting bars); deeply cleft (bi- or trifid). The operculum oblique, rostrate. Setae about 0.5–10 mm long; straight.

Ecology. More or less aquatic, or in wet places (usually periodically submerged); occurring in basic habitats, or neutral pH conditions (mainly on regularly inundated rocks and tree bases, with C. fontinaloides and C. riparius mainly in basic locations, but C. mucronatus sometimes occurs away from water).

Cytology. Haploid chromosome number, n = 13 (C. fontinaloides).

British representation. 2 species. Cinclidotus. 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 Dicranideae; Order Pottiales.

Illustrations. • Cinclidotus fontinaloides, with Dialytrichia: Dixon. C. fontinaloides. D. mucronata. • Cinclidotus, with Tortula (Pottiaceae): 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.’.