The Moss Families of the British Isles


L. Watson and M. J. Dallwitz


Gametophyte. Acrocarpous (robust plants, resembling Polytrichum in habit); forming tufts, or forming patches. Mature plants 20–90 mm high. Stems tomentose below. The leaves lanceolate to narrowly lanceolate, or narrowly lanceolate to linear; spiral; crisped when dry. Leaf bases sheathing. The leaves 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 pointed; acuminate. Leaf blade margins flat, or involute or incurved; distally obscurely to coarsely dentate. Leaf blades not conspicuously bordered. The basal leaf cells longitudinally much elongated (at least a few of them orange); narrowly rectangular, or linear; papillose, or smooth. The angular cells not well differentiated. The mid-leaf cells more or less isodiametric, or more or less isodiametric to somewhat longitudinally elongated; quadrate, or rectangular, or hexagonal to rounded; papillose (sometimes, in T. norvegica), or smooth. The walls of the mid-leaf cells thin, or thin to thick; straight.

Plants dioecious.

Sporophyte. Capsules exserted; inclined to pendulous; symmetrical; curved (or kinked); clavate, or ellipsoid to ovoid; striate and becoming regularly furrowed when dry and empty. Calyptra symmetrical; splitting down one side. Capsules with a peristome. The peristome double. The peristome teeth 16; not grouped; not deeply cleft; thin, membranous, and transversely barred; exteriorly with a fine longitudinal dividing line between the transverse bars. The inner peristome well developed; with a basal membranous ring; without “processes”; ciliate (the cilia in pairs or fours, opposite the teeth). Setae long; straight (?).

Ecology. Very rare, growing on soil at high altitudes.

British representation. 3 species. Timmia (Timmias and Indian Feather-moss). Northern Scotland and Ireland.

Classification. Class Bryopsida; Subclass Funariideae; Order Timmiales.

Illustrations. • Timmia austriaca and T. norvegica: Dixon. Timmia austriaca Hedw. Timmia norvegica Zett.

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.’.