Riccardia umida
Common names
liverwort
Biostatus
Native
Current conservation status
The conservation status of the New Zealand hornwort and liverwort flora is reassessed using the New Zealand Threat Classification System (NZTCS). A full list is presented, along with a statistical summary and brief notes on the most important changes. This list replaces all previous NZTCS lists for New Zealand hornworts and liverworts which previously had been part of a generic bryophyte conservation status assessment that included mosses. Authors: P.J. de Lange, D. Glenny, K. Frogley, M.A.M. Renner, M. von Konrat, J.J. Engel, C. Reeb and J.R. Rolfe.
Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2020 | Data Deficient | Qualifiers: IE, OL
Category
Non-vascular
Structural class
Liverworts
Detailed description
Dioicous. Thallus small, light green and creeping. Growth indeterminate, branching alternate to subopposite and simply pinnate to slightly bipinnate. Thalli c.5-10 mm long, 225-310 microns wide. Apices rounded. Mucilage papillae or papillae-like cells 18-170 x 15-29 microns, persisting dorsally and ventrally though less pronounced on ventral surface, sometimes sparse on both surfaces. Rhizoids ventral. Stolons and gemmae not seen. Axis plano- to biconvex with subacute to rounded margins, thallus 110-155 microns, and 7-8 cells thick; cell walls thin to slightly thickened with cell depths even throughout thallus. Epidermal cell walls lacking ornamentation. Dorsal epidermal cells tending to be rectangular to hexagonally elongate 21-91 x 11-28 microns, and 13-25 microns deep. Ventral epidermal cells hexagonally elongate to approximately isodiametric, 32-148 x 16-31 microns, and 13-26 microns deep. Ventral subepidermal cells similar, 32-70 x 21-28 microns. Internal cells 11-29 microns deep. Oil-bodies: epidermal cells with (0-)3 pale brown, granular, spherical to slightly ellipsoidal oil-bodies, 4-10 x 3-8 microns. Subepidermal oil-bodies (0-)6, similar but slightly longer. Endophytic mycorrhizae inconspicuous. Male branches solitary or branched, arising from main axis, sessile; antheridial cavities in 1-3 pairs on dorsal surface; separated by 2 or more cells. Female branches short, solitary, on the main axis with 1-2 pairs of archegonia. Calyptra and sporophyte unknown.
Distribution
Endemic. Campbell Island
Substrate details
Alpine. Terricolous on damp peat in herbfields
Threats
Known only from the type gathering. Probably not facing any specific threats. However, it has not been collected since 1987. Campbell Island, its only known location is a Nature Reserve and part of a World Heritage Park.
Detailed taxonomy
Genus
Family
Synonyms
None (first described in 1989)
Endemic genus
No
Endemic family
No
Ecology
Fruiting
Fruits not known
Other information
Previous conservation statuses
The conservation status of the New Zealand hornwort and liverwort flora is reassessed using the New Zealand Threat Classification System (NZTCS). A full list is presented, along with a statistical summary and brief notes on the most important changes. This list replaces all previous NZTCS lists for New Zealand hornworts and liverworts which previously had been part of a generic bryophyte conservation status assessment that included mosses. Authors: P.J. de Lange, D. Glenny, K. Frogley, M.A.M. Renner, M. von Konrat, J.J. Engel, C. Reeb and J.R. Rolfe.
Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2014 | Data Deficient | Qualifiers: IE, OL
2009 | Threatened – Nationally Critical | Qualifiers: OL, DP
Referencing and citations
References and further reading
Brown, E.A.; Braggins, J.E. 1989: A revision on the genus Riccardia S.F. Gray in New Zealand with notes on the genus Aneura Dum. Journal of the Hattori Botanical Labratory 66: 1-132.
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange (27 August 2006). Description adapted from Brown & Braggins (1989).