The liverwort genera (Bryophyta: Hepaticae and Anthocerotae) of Britain and Ireland
Gametophyte. Plants minute, forming reddish-brown patches, ascending shoots 3–6 mm long, leafy. The branching when present, lateral (arising from leafless horizontal stems, the shoots and horizontal stems producing small-leaved innovations, the female shoots producing innovations from beneath successive inflorescences, the innovations and shoots arising laterally); not dichotomous. Acrogynous. The leaf cells small, without trigones.
The leafy shoots dorsiventral, with the two ranks of laterals more or less equal in size and the ventral rank lacking. The vegetative leaves more or less symmetrical. The vegetative leaves more or less transversely inserted (the lower minute and distant, the upper larger and imbricate); alternate; overlapping and distant. The leaf margins entire; incurved or inflexed, or flat; not or only slightly dorsally decurrent. The vegetative leaves more or less symmetrical, ovate-quadrate, transversely inserted, bilobed (to about 2/3, the lobes acute and the sinus narrow); not complicate-bilobed. The ventral lobes similar in size to the dorsal ones. Underleaves absent. The cells of the gametophyte with numerous small chloroplasts. Gemmae absent.
The plants dioecious.
Male inflorescences apical and intercalary, the bracts loosely imbricate, very concave, larger and broader than the leaves, about 1/3 bilobed, the lobes obtuse. Male bracts subtending a single antheridium (this large). Female inflorescences terminating stems and innovant branches. Female bracts present (distichous, larger than the leaves, bilobed to about halfway, the lobes obtuse). Perianth present; half-exserted, ellipsoid, frontally compressed, sulcate and obscurely trigonous. Perianth distally plicate (deeply 6–10 plicate towards the rounded apex and denticulate mouth). Perianth not beaked.
Sporophyte. The sporophyte elevated by elongation of the seta, with no intercalary meristem. The capsule ovoid to shortly cylindrical. The capsule wall 2 layered (? - the outer wall with nodular thickenings, the inner with semi-annular thickenings). The capsule brown, not green. The spores unicellular when shed. Elaters present; closely bispirally thickened (reddish-brown, about half as long as the spores).
British representation. 1 species (E. myriocarpus); England, Wales, Scotland, and Ireland.
Classification. Class/Division Hepaticae. Subclass/Class Jungermanniidae. Order Jungermanniales. Family Lophoziaceae.
Illustrations. • E. myriocarpus: Jameson, in Macvicar (1926). • E. myriocarpus: Pearson fig. LXXVIII (1902). • E. myriocarpus: Pearson fig. LXXVIII 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’.