The liverwort genera (Bryophyta: Hepaticae and Anthocerotae) of Britain and Ireland
Gametophyte. Plants slender to medium sized, green to reddish brown or brown, leafy. Stems irregularly branching ventrally. The branching ventral. The stems with no clear differentiation of cortical and central tissues. Plants with flagella or flagelliform shoots or branches (arising ventrally). Acrogynous. The leaf cells without trigones. Rhizoids present; rather numerous below and on flagella, scarce above, 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 to distant; not decurrent, succubous. The leaf margins entire; not or only slightly dorsally decurrent. The vegetative leaves 1/6–1/3 bilobed (the lobes obtuse to rounded); without vittae. Underleaves smaller than the laterals though well developed and conspicuous (small, lanceolate, acute or bilobed). The cells of the gametophyte with numerous small chloroplasts. Gemmae common to absent.
The plants dioecious.
Male inflorescences terminal on long or short branches, sometimes becoming intercalary, the closely imbricate bracts similar to the leaves but more concave. Female inflorescences on short ventral branches. Female bracts present (bilobed, the margins sometimes with a short tooth on one or both sides). Female bracts similar in size to the (upper) leaves, or larger than the (upper) leaves. Bracteole present (similar to the bracts). Perianth present; cylindrical, with a crenulate mouth. Perianth distally plicate.
Sporophyte. The sporophyte long-exserted, elevated by elongation of the seta, with no intercalary meristem. The capsule ovoid to shortly cylindrical. The capsule wall 2 layered (?). The capsule not green (brown). The spores unicellular when shed. Elaters present; bispirally thickened; free (?).
British representation. 2 species; England, Wales, Scotland, and Ireland.
Classification. Class/Division Hepaticae. Subclass/Class Jungermanniidae. Order Jungermanniales. Family Cephaloziaceae.
Illustrations. • C. fluitans (as Cephalozia): Jameson, in Macvicar (1926). • C. fluitans (as Cephalozia): Pearson fig. LXIII (1902). • C. fluitans (as Cephalozia): Pearson fig. LXIII (legend). • C. francisci (as Cephalozia): Jameson, in Macvicar (1926). • C. francisci (as Cephalozia): Pearson fig. LXII (1902). • C. francisci (as Cephalozia): Pearson fig. LXII 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’.