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

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L. Watson and M. J. Dallwitz

Marsupella Dum.

Gametophyte. Plants minute to large, in tufts or patches, commonly brown, leafy. The stems simple to sparingly branched, basally stoloniferous. Acrogynous. The leaf cells thin- to thick-walled, with trigones, or without trigones. Rhizoids present; colourless to violet or purple.

The leafy shoots not dorsiventral, with two equal ranks of similar lateral leaves and ventral leaves lacking; julaceous, or not julaceous. The vegetative leaves more or less symmetrical. The vegetative leaves more or less transversely inserted, or transversely inserted to obliquely inserted; alternate; overlapping to distant (less effectively hiding the stems than in Gymnomitrion); spreading to appressed, more or less concave, when not secund slightly succubous; undivided to bilobed (only slightly to 1/2 bilobed, the lobes more or less equal); without vittae. The cells of the gametophyte with numerous small chloroplasts. Gemmae absent.

The plants with terminal inflorescences, dioecious, or bisexual; when bisexual, having the gametangia grouped into bracteate inflorescences; when bisexual, paroecious.

Perigynium present and well developed, or absent or vestigial (often marsupial, usually orientated on the same axis as the stem and well developed, or short and then with the sporophyte deeply embedded). Marsupia present as downgrowths from stem apices, surrounding the developing sporophytes and carrying them into the substrate, or present but vestigial, or absent. Female bracts present (4–6, larger than the preceding male bracts when paroecious or leaves when dioecious, erect, basally connate with one another and with the perianth). Perianth present (usually shortly conical or ovoid-conical with the mouth crenulate to crenulate-dentate, sometimes immersed in the female bracts), or absent (then represented by 1–2 circles of scales). Calyptra present and well developed (this unistratose, not derived from the perigynium, surrounded basally by sterile archegonia).

Sporophyte. The sporophyte elevated by elongation of the seta, with no intercalary meristem. The capsule globose. The capsule wall 2 layered. The spores unicellular when shed. Elaters present; bispirally thickened, or thickend via 3–4 spirals; free.

British representation. 11 species; England, Wales, Scotland, and Ireland.

Classification. Class/Division Hepaticae. Subclass/Class Jungermanniidae. Order Jungermanniales. Family Gymnomitriaceae.

Illustrations. • M. adusta: Jameson, in Macvicar (1926). • M. adusta (as olivacea): Pearson fig. CLXVII (1902). • M. adusta (as olivacea): Pearson fig. CLXVII legend. • cf. M. adusta (as Cesia brevissima): Pearson fig. CLXXVI (1902). • cf. M. adusta (as Cesia brevissima): Pearson fig. CLXXVI legend. • M. alpina: Jameson, in Macvicar (1926). • cf. M. alpina (as Cesia): Pearson fig. CLXXII (1902). • cf. M. alpina (as Cesia): Pearson fig. CLXXII legend. • cf. M. boeckii (as stableri): Pearson fig. CLXX (1902). • cf. M. boeckii (as stableri): Pearson fig. CLXX legend. • M. brevissima: Jameson, in Macvicar (1926). • M. brevissima (as Cesia crassifolia): Pearson fig. CLXXIV (1902). • M. brevissima (as Cesia crassifolia): Pearson fig. CLXXIV legend. • cf. M. brevissima (as Cesia conferta): Pearson fig. CLXXV (1902). • cf. M. brevissima (as Cesia conferta): Pearson fig. CLXXV legend. • M. emarginata: Pearson fig. CLXIII (1902). • M. emarginata: Pearson fig. CLXIII legend. • M. emarginata vars. robusta and saccata: Pearson fig. CLXIV (1902). • M. emarginata vars. robusta and saccata: Pearson fig. CLXIV legend. • M. funkii: Pearson fig. CLXVI (1902). • M. funkii: Pearson fig. CLXVI legend. • M. sparsifolia: Pearson fig. 169 (1902). • M. sparsifolia: Pearson fig. 169 legend. • M. sphacelata: Pearson fig. CLXV (1902). • M. sphacelata: Pearson fig. CLXV legend. • cf. M sprucei (as ustulata): Pearson fig. CLXVIII (1902). • cf. M sprucei (as ustulata): Pearson fig. CLXVIII 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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