The liverwort genera (Bryophyta: Hepaticae and Anthocerotae) of Britain and Ireland
Gametophyte. Plants thalloid, not leafy (with a thick midribe and unistratose, crisped wings). Anacrogynous. Rhizoids present; colourless, or brown (or straw-coloured); of one kind, all smooth.
The cells of the gametophyte with numerous small chloroplasts. The thallus branching dichotomously (furcate); without a conspicuous conducting strand; with ventral scales (uniseriate, concealed among the rhizoids at the midrib margins, and ephemeral). Gemmae absent (?). The thallus without dorsal pores; without cavities.
The plants dioecious; with no grouping of gametangia into bracteate inflorescences. The antheridia numerous on the dorsal surface or towards the thallus apices, protected by bracts (protected by forwardly directed, toothed or lobes scales, the latter in M. hibernica coalescing to form chambers).
The archegonia and sporophytes with a pseudoperianth (this ellipsoid, the archegonia on the dorsal side of the thallus, surrounded by irregularly laciniate or toothed, more or less fused bracts).
Sporophyte. The sporophyte elevated by elongation of the seta, with no intercalary meristem. The capsule globose to shortly cylindrical. The capsule wall 3–6 layered. The capsule dehiscing via two valves, or dehiscing by four valves. Elaters present; bispirally thickened, or thickend via 3–4 spirals; free, or free to persistent on elaterophores. The elaterophores rudimentary or absent.
British representation. 2 species; England, Wales, Scotland, and Ireland.
Classification. Class/Division Hepaticae. Subclass/Class Jungermanniidae. Order Metzgeriales. Family Pallaviciniaceae.
Illustrations. • M. blyttii: Jameson, in Macvicar (1926). • M. blyttii (as Pallavicinia): Pearson fig. CXCIV (1902). • M. blyttii (as Pallavicinia): Pearson fig. CXCIV legend. • M. blyttii (as Pallavicinia): Pearson fig. CXCV (1902). • M. blyttii (as Pallavicinia): Pearson fig. CXCV legend. • M. hibernica: Jameson, in Macvicar (1926). • cf. M. hibernica (as Pallavicinia): Pearson fig. CXCII (1902). • legCXCII.jpg<@subject. • cf.. • M.. • hibernica. • (as. • Pallavicinia):. • Pearson. • fig.. • CXCII. • legend>. • cf. M. hibernica vars. leptodesma and wilsoniana (as Pallavicinia): Pearson fig. CXCIII (1902). • legCXCIII.jpg<@subject. • cf.. • M.. • hibernica. • vars.. • (as. • Pallavicinia):. • Pearson. • fig.. • CXCIII. • legend>.
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’.