The liverwort genera (Bryophyta: Hepaticae and Anthocerotae) of Britain and Ireland
Gametophyte. Plants minute to robust, leafy. The stems with cortical cells clearly differentiated from the cells of the central strand. Plants with flagella or flagelliform shoots or branches to with neither flagella nor flagelliform shoots or branches (having more or less attenuated branch tips). Acrogynous. The leaf cells without trigones. Rhizoids present.
The leafy shoots dorsiventral, with two equal ranks of lateral leaves and a third, ventral rank of smaller underleaves. The vegetative leaves more or less transversely inserted to obliquely inserted; alternate; overlapping to distant; symmetrical, incubous. The leaf margins more or less multi-ciliate. The vegetative leaves so deeply divided as to be almost reduced to long, slender, bi- to uniseriate segments (very deeply 2–3(-4) lobed, the lobes uniseriate save sometimes for a basal 1–2 pairs); without vittae. Underleaves similar in size to the laterals to smaller than the laterals though well developed and conspicuous (2–4 lobed). The cells of the gametophyte with numerous small chloroplasts.
The plants dioecious, or bisexual; having the gametangia grouped into bracteate inflorescences; when bisexual, autoecious.
Male inflorescences on short or very short branches, the antheridia in the axils of 3–6 concave bracts that are smaller than the leaves. The antheridial stalks 1 seriate. Female inflorescences on short or very short branches. Female bracts present (larger than the leaves, shallowly to deeply 3–4 lobed). Perianth present; unistratose, narrowed to the crenulate or long-ciliate mouth.
Sporophyte. The sporophyte elevated by elongation of the seta, with no intercalary meristem. The capsule wall 3–5 layered. The spores unicellular when shed.
British representation. 2 species (T. murphyae, T. nematodes); England and Ireland.
Classification. Class/Division Hepaticae. Subclass/Class Jungermanniidae. Order Jungermanniales. Family Lepidoziaceae.
Illustrations. • T. murphyae: Paton 1999.
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’.