The liverwort genera (Bryophyta: Hepaticae and Anthocerotae) of Britain and Ireland
Gametophyte. Plants small to medium sized, leafy. Shoots prostrate, the sparse branching ventral or apical. The stems with no clear differentiation of cortical and central tissues. Acrogynous. The leaf cells with trigones (these small), or without trigones (mostly).
The leafy shoots dorsiventral, with two equal ranks of lateral leaves and a third, ventral rank of smaller underleaves. The vegetative leaves very obliquely inserted; alternate; overlapping to distant; spreading horizontally, plane to slightly convex, usually determinable as incubous; ovate to broadly so or triangular, undivided, or bilobed (apically rounded to acute or bidentate); without vittae. Underleaves smaller than the laterals though well developed and conspicuous (quite large, wider than the stem, rounded, entire to deeply bilobed, toothed or not). The cells of the gametophyte with numerous small chloroplasts. Gemmae common (spherical to ellipsoid, 1–2 celled and very thin walled, produced in fascicles at the tips of usually attenuated shoots).
The plants dioecious, or bisexual; having the gametangia grouped into bracteate inflorescences; autoecious (when bisexual,), or paroecious.
Male inflorescences on dwarf ventral branches, the 3–5 pairs of bracts very small. Female inflorescences on dwarf ventral branches. Perigynium present and well developed (marsupial). Marsupia present as downgrowths from stem apices, surrounding the developing sporophytes and carrying them into the substrate (this large, fleshy, rhizoid-covered and with or without peristent female bracts around its mouth, subterranean). Female bracts present (two to three pairs, much smaller than the leaves, scale-like, ephemeral or persisting around the mouth of a marsupium). Perianth present. Calyptra seemingly incorporated in the marsupium?.
Sporophyte. The sporophyte elevated by elongation of the seta, with no intercalary meristem. The capsule long pedicellate, ovoid to elongate-cylindrical. The capsule wall 2 layered. The capsule having erect, spirally twisted valves. The spores unicellular when shed. Elaters present; bispirally thickened; free.
British representation. 8 species; England, Wales, Scotland, and Ireland.
Classification. Class/Division Hepaticae. Subclass/Class Jungermanniidae. Order Jungermanniales. Family Calypogeiaceae.
Illustrations. • C. arguta: Jameson, in Macvicar (1926). • cf. C. arguta (as Kantia): Pearson fig. LIII (1902). • cf. C. arguta (as Kantia): Pearson fig. LIII legend. • C. azurea (as trichomanis): Jameson, in Macvicar (1926). • cf. C. azurea (as Kantia trichomanis): Pearson fig. LI (1902). • cf. C. azurea (as Kantia trichomanis): Pearson fig. LI legend. • C. fissa: Jameson, in Macvicar (1926). • cf. C. fissa (as Kantia sprengelii): Pearson fig. LII (1902). • cf. C. fissa (as Kantia sprengelii): Pearson fig. LII legend. • C. muelleriana (as submersa): Jameson, in Macvicar (1926). • C. neesiana: Jameson, in Macvicar (1926). • C. sphagnicola: Jameson, in Macvicar (1926). • C. suecica: Jameson, in Macvicar (1926).
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 liverwort genera (Bryophyta: Hepaticae and Anthocerotae) of Britain and Ireland. Version: 24th February 2016. delta-intkey.com’.