| | The liverwort genera (Bryophyta: Hepaticae and Anthocerotae) of Britain and Ireland |
Including Chiloscyphus p.p.
Gametophyte. Plants small to large, whitish- to yellowish-green or green leafy. The stems usually creeping, branching irregularly. The stems not translucent. Acrogynous. The leaf cells thin walled, but small with trigones, or without trigones. Rhizoids present (bunched at the bases of the underleaves); colourless.
The leafy shoots dorsiventral, with two equal ranks of lateral leaves and a third, ventral rank of smaller underleaves. The vegetative leaves not wedge-shaped; very obliquely inserted; alternate; usually overlapping; succubous; undivided to bilobed (truncate or emarginate to bilobed almost to halfway, with a wide sinus, sometimes irregularly spinosely toothed apically); without vittae. Underleaves smaller than the laterals though well developed and conspicuous (bilobed, sometimes toothed on either side). The cells of the gametophyte with numerous small chloroplasts. Gemmae common to absent (when present, 1-multicellular).
The plants dioecious, or bisexual; when bisexual, having the gametangia grouped into bracteate inflorescences, or with no grouping of gametangia into bracteate inflorescences.
Male inflorescences when dioecious terminal or becoming intercalary, the basally saccate bracts subtending the solitary antheridia. Male bracts subtending a single antheridium. Female inflorescences terminal on main axes and branches. Female bracts present (usually bilobed, resembling the stem leaves, but often more dentate or ciliate). Bracteole present (similar to or smaller than the bracts). Perianth present; longly-emergent, trigonous above and often keel-winged, the wide mouth 3-lobed with dentate or ciliate lobes. Calyptra present and well developed (free).
Sporophyte. The sporophyte elevated by elongation of the seta, with no intercalary meristem. The capsule ovoid. The capsule wall 4–6 layered. The spores unicellular when shed. Elaters present (reddish brown); bispirally thickened; free.
British representation. 5 species; England, Wales, Scotland, and Ireland.
Classification. Class/Division Hepaticae. Subclass/Class Jungermanniidae. Order Jungermanniales. Family Geocalycaceae.
Illustrations. • L. bidentata: Jameson, in Macvicar (1926). • L. bidentata: Pearson fig. CI (1902). • L. bidentata: Pearson fig. CI legend. • L. bidentata (as L. cuspidata): Pearson fig. CII (1902). • L. bidentata (as L. cuspidata): Pearson fig. CII legend. • L. fragrans: Jameson, in Macvicar (1926). • cf. L fragrans (as L. spicata): Pearson fig. CIV (1902). • cf. L fragrans (as L. spicata): Pearson fig. CIV legend. • L. heterophylla: Jameson, in Macvicar (1926). • L. heterophylla: Pearson fig. CIII (1902). • L. heterophylla: Pearson fig. CIII legend.
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 liverwort genera (Bryophyta: Hepaticae and Anthocerotae) of Britain and Ireland. Version: 5th August 2019. delta-intkey.com’.
