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| The moss families (Bryophyta, Musci) of Britain and Ireland |
~Hookeriaceae
Gametophyte. Pleurocarpous; mat or turf forming (the plants slender to moderately robust, soft and glossy). Primary stems procumbent (stems irregularly pinnately branched, tomentose). Mature plants with the procumbent shoots to about 80 mm long in C. laetevirens. Shoots complanate. The leaves more or less markedly asymmetrical; broadly ovate; spiral (5–8 ranked). Leaf bases not decurrent. The leaves double-nerved. The leaf nerves not extending beyond the middle of the leaf to extending beyond the middle of the leaf, but not to the tip (to about halfway). Leaf blade apices pointed; apiculate. Leaf blade margins unistratose to bi-stratose; entire to denticulate (apically denticulate). Leaf blades narrowly bordered. The basal leaf cells somewhat longitudinally elongated; irregularly to elongate hexagonal; smooth. The walls of basal leaf cells thin; straight. The angular cells not well differentiated. The mid-leaf cells somewhat longitudinally elongated; irregularly hexagonal, or rounded; smooth. The walls of the mid-leaf cells thin; straight.
Plants monoecious, or dioecious; autoecious, or synoecious.
Sporophyte. Capsules exserted; inclined to horizontal; symmetrical; straight; sub-cylindric, or ovoid; not waisted; neither flattened nor angular; without an externally conspicuous apophysis; smooth; with an annulus (comprising a single row of fugacious cells). Calyptra hairy; symmetrical; with two or more splits. Capsules with a peristome. The peristome double. The peristome teeth 16; not grouped; not deeply cleft; not perforated; thin, membranous, and transversely barred; exteriorly with a fine longitudinal dividing line between the transverse bars. The inner peristome about equalling the outer; with a basal membranous ring (this high); with elongated “processes” (these keeled). The processes of the inner peristome 16; alternating with the teeth of the outer peristome. The inner peristome ciliate, or without cilia (?). The operculum rostrate. Setae long, stout; straight; smooth.
Ecology. In wet places. On wet shaded rocks, in ravines, caves and crevices near waterfalls.
Representation in Britain and Ireland. 1 species. Cyclodictyon (Bright-Green Cave-moss). Southwest England and Ireland (extinct in England?).
Classification. Class Bryopsida; Subclass Bryideae; Order Hookeriales.
Illustrations. • Cyclodictyon, Daltonia, and Hookeria: Dixon. PILOTRICHACEAE: I, Cyclodictyon laetevirens (Hook. & Tayl.) Mitt. DALTONIACEAE: H, Daltonia splachnoides (Sm.) Hook. & Tayl. HOOKERIACEAE: J, Hookeria lucens (Hedw.) Sm.
From Dixon and Jameson (1924), the unscaled screen display approximately doubling the magnifications given with their individual figures. 1, leaf, or stem leaf where these differ; 2, branch-leaf; 3, perichaetial leaf; 4, perigonial leaf; 5, capsule; 6, peristome; 7, calyptra; 8, spores; 9, inflorescence; 10, gemmae; 11, paraphyllia; 12, stoma of capsule; *, plant, or part of one. Qualifications: a, apex; b, base; c, cells at one third from the apex; cv, ventral aspect of cells; cd, dorsal aspect of cells; bc, basal cells; x, section. Daltonia splachnoides. Cyclodictyon laetevirens. Hookeria lucens. • Cyclodictyon, with Fontinalaceae, Cryphaeaeae, Hookeriaceae,: Berkeley. PILOTRICHACEAE: 6, Cyclodictyon laete-virens (Hook. & Tayl.) Mitt.; a, leaf; b, capsule. From Berkeley (1863). FONTINALACEAE: 1, Fontinalis squamosa Hedw.; a, leaf; 2, capsule and perichaetium; c, detail of part of outer and inner peristome. 2, Fontinalis antipyretica Hedw.; a, leaf; b, leaf cells; c, capsule and perichaetium; d, cayptra; e, capsule with peristome exposed. CRYPHAEACEAE: 3, Cryphaea heteromalla (Hedw.) Mohr; a, leaf; b, leaf cells; c, capsule and perichaetium; d, calyptra. HOOKERIACEAE: 5, Hookeria lucens (Hedw.) Smith; a, leaf; b, capsule; c, calyptra; d, part of the peristome. DALTONIACEAE: 4, Daltonia splachnoides (Sm.) Hook. & Tayl.; a, leaf; b, capsule; c, calyptra; d, part of the peristome. The approximate 1 cm scale added at upper left applies to the whole plant (habit) illustrations only.
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, 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. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2005 onwards. The moss families (Bryophyta, Musci) of Britain and Ireland. Version: 5th August 2019. delta-intkey.com’.
