The New Zealand Plant Conservation Network

Species

Grimmia plagiopoda

Common Name(s)

Moss

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

Previous Conservation Status

2004 - Threatened - Nationally Critical

Qualifiers

2009 - OL, TO

Authority

Grimmia plagiopoda Hedw.

Family

Grimmiaceae

Flora Category

Non Vascular - Native

Synonyms

Grimmia argentea R.Br.bis

Distribution

Indigenous. New Zealand: South Island (Castle Hill Basin). Otherwise recorded from sparingly from (Seppelt & Green 1998) Antarctica, Australia, South America and elsewhere throughout the world

Habitat

Saxicolous. Montane. Confined to limestone outcrops within the Castlehill karstfield. Castlehill is now surrounded by tussock grassland but it was formerly forested.

Features

Saxicolous, forming minute, rounded, bright silvery cushions on limestone rock. Stems short c.5 mm tall, closely matted together, densely and turgidly branched. leaves crowded, broadly ovate or oblong, deeply concave; margins plane not thickened. Nerve weak and narrow. Hyaline point usually longer than lamina, wide and rough, usually branched one or more times, irregularly dentate and variably flexuose or geniculate. Cells non-sinuose; the upper ones rather large 9-12 µm, those below widely oblong. Seta very short, curved. Capsule completely immersed, almost sessile, swollen at the base on one side. Peristome teeth pale-yellow, thin, delicate, irregularly cleft at apex. Operculum conic, with a short erect beak. Calyptra small. mitriform. Spores 12 µm diameter.

Similar Taxa

Distinguished from other New Zealand Grimmia by the capsule which is deeply immersed amongst the leaves, basally swollen and set asymmetrically on the seta; by the broad leaves whose cells are short and wide below; and by the hyaline point which is characteristically longer than the lamina, flexuose or geniculate, usually branched one or more times, and irregularly dentate.

Fruiting

Fruiting material is known but there is no data on fruiting times

Threats

Grimmia plagiopoda is known from only a single area in the Castlehill portion of the Tresslick Basin. There it is confined to limestone outcrops where it is threatened by rock climbing. Over the last two decades, as rock climbing has increased in popularity this minute moss has seriously declined, presumably because plants are scuffed out, trampled or dislodged by ropes. Currently there is little management of the situation.

Endemic Taxon

No

Endemic Genus

No

Endemic Family

No

This page last updated on 8 Nov 2013