The New Zealand Plant Conservation Network

Species

Radula javanica

Common Name(s)

liverwort

Current Conservation Status

2009 - Range Restricted

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 - DP, SO

Authority

Radula javanica Gottsche Lindenb. et Nees

Family

Radulaceae

Flora Category

Non Vascular - Native

Structural Class

Liverwort

Synonyms

None

Distribution

Indigenous. Kermadec Islands (Raoul Island). Widespread in northern Australia, western Oceania and Indonesia

Features

Plants forming patches of loosely intertwined bright green to dark green stems on tree trunks and rocks. Shoots 2000 micrometre wide, 40-50 mm long, irregularly branched, thecal branching common, distinguished from athecal branches by the presence of two small leaf like appendages at their base. Stems up to 120 micrometre diameter, cortical cells undifferentiated, of about 16 cell rows, medullary and cortical cells of similar size, medullar of c.20 cells, internal walls with strong irregular faintly concave trigones, sometimes confluent, medial walls also thickened, cells with irregular outline. strong brown pigment present in all walls, free external wall evenly thickened, to a slightly greater degree than internal walls. Lobes ovoid, rarely slightly falcate, contiguous to weakly imbricate, interior margin reaching opposite stem margin, weakly ampliate at stem insertion, insertion hooked, reaching stem mid-line, dorsal leaf free strip absent, stem obscured in dorsal view. Lobules c.one fifth lobe area, keel straight, relfexed at outer extremity, carinal region rounded, slightly inflated near the base of the lobule, attached to the stem for slightly more than half its interior length, free exterior margin distinctly concave, turning the apex away from the stem, antical margin smoothly rounded its entire length, running directly into the ampliate base, interior free margin never exceeding opposite stem margin. Lobules not imbricated, not obscuring stem in ventral view. One slime papillae present at the lobule apex, another two present near the base of the free interior margin. Insertion longitudinal, hooked apically, not attaining ventral stem midline, ventral leaf free strip 1-2 cell rows wide. Lobe cells isodiametric to hexagonal, thin walled with very faint trigones 18.3-28.9 x 14.5-21.7 micrometre. Lobule cells as for the lobe, though slightly elongated. Cell surfaces smooth. Oil bodies not seen. Rhizoids with brown pigmented walls. Leaves infrequently caducous on all axes, breaking off above lobe join, premeristematic outgrowths rarely seen on the antical margins of lobe still attached to the plants. Fertile material not seen in New Zealand.

Fruiting

Has not yet been observed in the wild

Threats

Known from very few gatherings but unlikely to be threatened. The bryophyte flora of Raoul Island has scarcely been studied by a trained bryologist. Plenty of habitat exists for this species there and there are no known human-induced threats

This page last updated on 20 Oct 2014