The liverwort genera (Bryophyta: Hepaticae and Anthocerotae) of Britain and Ireland
Gametophyte. Plants leafy. Acrogynous. The leaf cells very large, with trigones (these large and bulging). Rhizoids present (in tufts at leaf bases); long, colourless.
The leafy shoots dorsiventral, with two equal ranks of lateral leaves and a third, ventral rank of smaller underleaves. The vegetative leaves obliquely inserted; alternate; overlapping; slightly decurrent on the dorsal side, succubous. The leaf margins entire; at least somewhat dorsally decurrent. The vegetative leaves rotund to oblong-rotund, undivided (concave or saccate only at the base, more or less orbicular except sometimes when gemmiferous); without vittae. Underleaves present but much reduced or vestigial (small and simple, subulate or filiform, mostly concealed by rhizoids). The cells of the gametophyte with numerous small chloroplasts. The chloroplast-containing cells with conspicuous oil bodies. Gemmae common to rare (often present at the margins of apical leaves); spherical to ovoid, 1–2 celled.
The plants dioecious.
Male inflorescences terminal, with 4–8 pairs of transverse, suberect bracts similar to the leaves, but basally saccate, generally subtending pairs of globose to ovoid antheridia. Male bracts subtending 2 antheridia. Female inflorescences terminal on the main stem or branches. Perigynium absent or vestigial. Female bracts present (similar to the leaves). Bracteole absent. Perianth present; emergent, laterally compressed with a broad, closed mouth.
Sporophyte. The sporophyte elevated by elongation of the seta, with no intercalary meristem. The capsule ovoid. The capsule wall 3–5 layered. The spores unicellular when shed. Elaters present; reddish-brown, bispirally thickened; free.
British representation. 2 species; England, Wales, Scotland, and Ireland.
Classification. Class/Division Hepaticae. Subclass/Class Jungermanniidae. Order Jungermanniales. Family Jungermanniaceae.
Illustrations. • M. anomala (as Leptoscyphus): Jameson, in Macvicar (1926). • M. anomala: Pearson fig. CX (1902). • M. anomala: Pearson fig. CX legend. • M. taylori (as Leptocscyphus): Jameson, in Macvicar (1926). • M. taylori: Pearson fig. CIX (1902). • M. taylori: Pearson fig. CIX (1902).
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’.