The New Zealand Plant Conservation Network

Species

Riccardia umida

Common Name(s)

Liverwort

Current Conservation Status

2009 - Threatened - Nationally Critical

Conservation status of New Zealand indigenous vascular plants, 2012
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2012 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2009 and replaces all previous NZTCS lists for vascular plants. Authors: Peter J. de Lange, Jeremy R. Rolfe, Paul D. Champion, Shannel P. Courtney, Peter B. Heenan, John W. Barkla, Ewen K. Cameron, David A. Norton and Rodney A. Hitchmough. File size: 792KB

Qualifiers

2009 - OL, DP

Authority

Riccardia umida E.A.Brown

Family

Aneuraceae

Flora Category

Non Vascular - Native

Structural Class

Liverwort

Synonyms

None (first described in 1989)

Distribution

Endemic. Campbell Island

Features

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.

Fruiting

Fruits not known

Threats

Known only from the type gathering. Probably not threatened. However, it has not been colelcted since 1987. Campbell Island, its only known location is a Nature Reserve and part of a World Heritage Park.

This page last updated on 20 Oct 2014