The liverwort genera (Bryophyta: Hepaticae and Anthocerotae) of Britain and Ireland

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L. Watson and M. J. Dallwitz

Riccardia S.F. Gray

~ Aneura.

Gametophyte. Plants thalloid, not leafy (the thallus pale to dark green, circular to concavo-convex in section). Anacrogynous. Rhizoids of one kind, all smooth.

The cells of the gametophyte with numerous small chloroplasts. The chloroplast-containing cells with conspicuous oil bodies (1–15 per cell), or without oil bodies. The thallus irregularly 1–4 pinnately branching, or palmately branching; not greasy in appearance; without a conspicuous conducting strand; without ventral scales. Gemmae common, or rare, or absent. The thallus without gemma-receptacles (gemmae often present at the thallus apices,endogenous, 1–3 celled); without dorsal pores; without cavities.

The plants dioecious, or bisexual (then monoecious); when monoecious, autoecious.

Calyptra present and well developed (1–2 cells thick).

Sporophyte. The sporophyte elevated by elongation of the seta, with no intercalary meristem. The capsule dehiscing by four valves. The spores unicellular when shed. Elaters present; unispirally thickened; persistent on elaterophores, or free and persistent on elaterophores. The elaterophores apical (the original elaterophore being represented by an indistinct apical thickening of the capsule wall, which splits into four on dehiscence and resulting in erect tufts of elaters at the valve apices).

British representation. 5 species; England, Wales, Scotland, and Ireland.

Classification. Class/Division Hepaticae. Subclass/Class Jungermanniidae. Order Metzgeriales. Family Aneuraceae.

Illustrations. • R. incurvata (as Aneura) Jameson, in Macvicar (1926). • R. chamedryfolia (as Aneura sinuata): Pearson fig. CCIII (1902). • R. chamedryfolia (as Aneura sinuata): Pearson fig. CCIII legend. • R. latifrons (as Aneura): Jameson, in Macvicar (1926). • R. latifrons (as Aneura): Pearson fig. CCII (1902). • R. latifrons (as Aneura): Pearson fig. CCII legend. • R. multifida (as Aneura): Jameson, in Macvicar (1926). • R. multifida (as Aneura): Pearson fig. CC (1902). • R. multifida (as Aneura): Pearson fig. CC legend. • R. multifida (as Aneura ambrosioides): Pearson fig. CCI (1902). • R. multifida (as Aneura ambrosioides): Pearson fig. CCI legend. • R. palmata (as Aneura): Pearson fig. CXCIX (1902). • R. palmata (as Aneura): Pearson fig. CXCIX 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’.

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