The Moss Families of the British Isles

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L. Watson and M. J. Dallwitz

Ephemeraceae

In Dixon’s Funariaceae.

Gametophyte. Acrocarpous (the tiny plants, annual, arising from the persistent protonema); often forming patches. Rosette plants. Mature plants 0.5–2.2 mm high. The leaves ovate to narrowly lanceolate; spiral (forming the rosettes); nerveless (or sometimes with a vestigial nerve in the upper part), or single-nerved. The leaf nerves when present, extending beyond the middle of the leaf, but not to the tip, or extending to the leaf tip; slightly excurrent, or not excurrent. Leaf blade apices pointed; apically acute, or acuminate. Leaf blade margins (sub-) entire, or denticulate to dentate. The basal leaf cells longitudinally much elongated; hexagonal, or rounded, or rhomboidal; smooth. The walls of basal leaf cells thin; straight. The angular cells not well differentiated. The mid-leaf cells longitudinally much elongated; hexagonal, or rounded, or rhomboidal; smooth. The walls of the mid-leaf cells thin to thick; straight.

Plants monoecious, or dioecious; when monoecious, autoecious, or synoecious (Micromitrium).

Sporophyte. Capsules immersed; symmetrical; more or less globose (but often apiculate); without an externally conspicuous apophysis; with an annulus, or without an annulus. Calyptra small (minute and persistent in Micromitrium, fugacious in Ephemerum); symmetrical. Capsules cleistocarpus (exhibiting only a rudimentary lid, but that of Micromitrium has a differentiated annulus, along which it dehisces under pressure); without a peristome. Setae very short.

Ecology. Often forming patches on damp, compressed soil or mud.

Cytology. Haploid chromosome number, n = 27 (recorded for E. cohaerens only).

British representation. 8 species. Ephemerum (Earth-mosses), Micromitrium (Millimetre Moss). 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. • Ephemerum and Micromitrium tenerum: Dixon. Ephemerum serratum Hampe. Micromitrium tenerum Crosby. E. praecox Walther & Morendo. • Ephemerum stellatum, E. cohaerens, E. sessile and E. recurvifolium: Dixon. Ephemerum stellatum Philib. Ephemerum cohaerens Hampe. Ephemerum sessile C. Müll. Ephemerum recurvifolium Boul.


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. http://delta-intkey.com’.

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