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| The liverwort genera (Bryophyta: Hepaticae and Anthocerotae) of Britain and Ireland |
Gametophyte. Plants thalloid, not leafy (forming rosettes, the thallus usually dark green with margins only rarely crisped, the epidermis with stomata). Anacrogynous (borne singly on the dorsal surface of the thallus).
The cells of the gametophyte each with a single, large chloroplast. The thallus branching dichotomously, or irregularly lobed; without a conspicuous conducting strand; without ventral scales; without cavities.
The plants dioecious, or bisexual (then monoecious).
Sporophyte. The sporophyte elevated via an intercalary meristem. The capsule elongate-cylindrical; with a central, longitudinal columella; green; dehiscing via two valves. The spores yellowish, unicellular when shed. Elaters present; mostly bent, (1-)2-several celled (‘pseudo-elaters’); without spiral thickenings; free.
British representation. 1 species (P. laevis); England, Wales, Scotland, and Ireland.
Classification. Class/Division Anthocerotae. Order Anthocerotales. Family Anthocerotaceae.
Illustrations. • P. laevis: Jameson, in Macvicar (1926). • P. laevis (as Anthoceros levis): Pearson fig. CCXXVI (1902). • P. laevis (as Anthoceros levis): Pearson fig. CCXXVI (1902).
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, 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. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2005 onwards. The liverwort genera (Bryophyta: Hepaticae and Anthocerotae) of Britain and Ireland. Version: 5th August 2019. delta-intkey.com’.
