The Moss Families of the British Isles


L. Watson and M. J. Dallwitz



Gametophyte. Pleurocarpous; forming patches (these dark green). Primary stems procumbent (rhizome-like, the secondary stems decumbent to ascending and pinnately to bipinnately branched and inrolling when dry). Shoots not complanate. Paraphyllia present, or absent. The leaves of main stems and branches similar in form; bilaterally symmetrical to markedly asymmetrical; elliptical to oblong, or lingulate; spiral; faintly single-nerved. The leaf nerves not extending beyond the middle of the leaf. Leaf blade apices obtuse; not apiculate; apically rounded. Leaf blade margins revolute or recurved (on one side); distally sub-crenulate or entire. Leaf blades not conspicuously bordered. The basal leaf cells more or less isodiametric to longitudinally much elongated; hexagonal to rounded; smooth. The walls of basal leaf cells straight. The angular cells not well differentiated. The mid-leaf cells more or less isodiametric to somewhat longitudinally elongated; hexagonal to rounded; smooth. The walls of the mid-leaf cells thick; straight.

Plants dioecious.

Sporophyte. Capsules shortly exserted; erect; symmetrical; straight; sub-cylindric to ellipsoid; without an externally conspicuous apophysis; without an annulus. Calyptra hairy; symmetrical; splitting down one side. Capsules dehiscing via a lid; with a peristome. The peristome more or less single, or double. The peristome teeth 16; not grouped; not deeply cleft; perforated; thin, membranous, and transversely barred; exteriorly with a fine longitudinal dividing line between the transverse bars. The inner peristome if present, rudimentary; much shorter than the outer; with a basal membranous ring (usually reduced to the very short membrane); sometimes with elongated “processes” (these then rudimentary), or without “processes”. The operculum conical, or rostrate (conical-acuminate). Setae very short; straight.

Ecology. Mesophytic, or xerophytic; occurring in basic habitats. Usually on bark of trees in basic areas, rarely on basic walls or rocks.

British representation. 1 species. Leptodon (Prince-of-Wales Feather-moss). 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. • Leptodon smithii. Leptodon smithii. • Leptodon, with Neckera and Homalia (Neckeraceae): 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.’.