The Moss Families of the British Isles


L. Watson and M. J. Dallwitz


Cord-, Bladder- and Earth-mosses.

Excluding Dixon’s Ephemeraceae.

Gametophyte. Acrocarpous; forming patches, or the plants scattered. Mature plants 1.5–30 mm high. Plants exhibiting comal tufts of leaves, or without comal tufts. Stems not tomentose. The leaves neither sphagnoid nor leucobryoid. The leaves ovate to lanceolate, or lingulate, or spathulate to obovate (usually soft and concave); spiral; single-nerved. The leaf nerves extending beyond the middle of the leaf, but not to the tip (mostly), or extending to the leaf tip; not excurrent, or excurrent (occasionally). Leaf blades not lamellate. Leaf blade apices pointed; apically acute to acuminate. Leaf blade margins distally denticulate to dentate, or entire. Leaf blades bordered, or not conspicuously bordered. The basal leaf cells somewhat longitudinally elongated, or longitudinally much elongated; rectangular, or hexagonal, or rhomboidal; smooth. The walls of basal leaf cells thin; straight. The angular cells not well differentiated. The mid-leaf cells longitudinally much elongated, or somewhat longitudinally elongated to longitudinally much elongated; rectangular, or hexagonal, or rhomboidal; smooth. The walls of the mid-leaf cells thin; straight.

Plants monoecious; autoecious (nearly always), or paroecious (Physcomitrella).

Sporophyte. Capsules immersed (in Physcomitrella only), or exserted; erect, or inclined; symmetrical to asymmetrical; when elongated, straight, or curved; usually more or less pyriform (with numerous stomata at the base); with an externally conspicuous apophysis, or without an externally conspicuous apophysis. The apophysis when present, remaining smooth. Capsules smooth, or striate and becoming regularly furrowed when dry and empty. Calyptra symmetrical, or asymmetric (usually with an elongated apex); splitting down one side, or with two or more splits. Capsules cleistocarpus (Physcomitrella), or dehiscing via a lid; with a peristome (usually), or without a peristome. The peristome when present, single, or double. The peristome teeth when present, 16; thin, membranous, and transversely barred; when present, exteriorly with a fine longitudinal dividing line between the transverse bars. The inner peristome well developed to rudimentary; about equalling the outer; with a basal membranous ring, or without a basal membranous ring; when present, with elongated “processes”. The processes of the inner peristome when present, 16; when present, opposite the teeth of the outer peristome. The operculum convex, or mamillate (and blunt), or rostellate. Setae short to long; straight, or curved (often arcuate).

Ecology. In wet places to mesophytic. Not saxicolous.

Cytology. Haploid chromosome number, n = 9, 14, 18, 21, 26, 27, 28, 36, 52, 54, 56, and 72 (with Physcomitrium pyriforme ranging from 9 to 72!).

British representation. 10 species. Aphanorrhegma (Physcomitrella, Earth-mosses), Funaria (Cord-moss), Entosthodon (Cord-mosses), Physcomitrium (Bladder-mosses). 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 Funariideae; Order Funariales.

Illustrations. • Funaria (3 species), Aphanorrhegma and Physcomitrium: Dixon. • Funaria hygrometrica, F. microstoma and F. muhlenberhii: Dixon. • Funaria attenuata and Funaria hygrometrica: Berkeley. • Physcomitrella patens: Berkeley. • Funaria hygrometrica (by Curtis).

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.’.