The Moss Families of the British Isles

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L. Watson and M. J. Dallwitz

Theliaceae

Mouse-tail Mosses.

~Pterigynandraceae.

Gametophyte. Pleurocarpous; forming patches, or growing through other Bryophytes. Primary stems ascending or erect, irregularly branched, the branches julaceous. Stems not tomentose (but the older parts with sparse, long thin rhizoids). The leaves of main stems and branches similar in form; broadly ovate (very concave); spiral; faintly double-nerved, or single-nerved (then the single nerve forked). The leaf nerves not extending beyond the middle of the leaf. Leaf blade apices obtuse to pointed; apiculate, or not apiculate; apically rounded. Leaf blade margins distally crenulate to denticulate, or entire. Leaf blades not conspicuously bordered. The basal leaf cells more or less isodiametric to longitudinally much elongated; rectangular, or hexagonal, or rounded, or rhomboidal; papillose. The walls of basal leaf cells straight. The angular cells not well differentiated. The mid-leaf cells more or less isodiametric (M. julacea), or longitudinally much elongated (M. apiculata); hexagonal to rounded (M. julacea), or rounded to rhomboidal (M. apiculata); papillose. The walls of the mid-leaf cells thin to thick; straight.

Plants dioecious.

Sporophyte. Capsules exserted; erect, or erect to inclined (erect to sub-inclined); symmetrical; straight; more or less pyriform (? - “obovoid”); with an annulus. Calyptra very small (minute); symmetrical; splitting down one side. Capsules with a peristome. The peristome double. The peristome teeth 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 elongated “processes”; ciliate. The operculum bluntly conical. Setae short or long; curved.

Ecology. Mesophytic, or xerophytic; occurring in basic habitats. At high altitudes, on damp or dry basic soil among rocks or in rock crevices.

British representation. 2 species. Myurella. Northern Scotland, southern Scotland, Wales, and Ireland.

Classification. Class Bryopsida; Subclass Bryideae; Order Hypnales.

Comments. Small, slender plants, with fragile 1–15 mm long shoots, the branches conspicuously julaceous in M. julacea. See classificatory comment under Pterigynandraceae.

Illustrations. • Myuriaceae (Myuria), and Theliaceae (Myurella): Dixon. Myurium hochstetteri (Schimp.) Kindb. MYURIACEAE. Myurella julacea Br. Eur. THELIACEAE. Myurella tenerrima (Brid.) Lindb.


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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