Grimmia plagiopodia
Common names
dry rock moss
Biostatus
Native
Current conservation status
This is the first complete assessment of all known species of mosses found in the wild in Aotearoa New Zealand with a total of 560 species being assessed. The conservation status of mosses, published in the NZTCS database, replaces all previous assessments of mosses. Data supporting the 2025 NZTCS assessment of mosses has been published on the NZTCS database at https://nztcs.org.nz/reports/1155.
Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2025 | Threatened – Nationally Critical | Qualifiers: DPS, DPT, OL, TO
Category
Non-vascular
Structural class
Mosses
Detailed description
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.
Distribution
Indigenous. New Zealand: South Island (Castle Hill Basin Canterbury).
Otherwise recorded sparingly from Antarctica, Australia, South America and elsewhere throughout the world (Seppelt & Green 1998).
Habitat
Saxicolous. Montane. Confined to limestone outcrops within the Castle Hill karstfield. Castle Hill is now surrounded by tussock grassland but it was formerly forested.
Substrate details
Saxicolous on limestone.
Threats
Grimmia plagiopodia is known from only a single area in the Castle Hill portion of the Tresslick Basin. There it is confined to limestone outcrops, where it is threatened by rock climbing. As rock climbing has increased in popularity over the last two decades, 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.
Detailed taxonomy
Genus
Family
Synonyms
Grimmia argentea R.Br.bis
Endemic taxon
No
Endemic genus
No
Endemic family
No
Ecology
Fruiting
Fruiting material is known but there is no data on fruiting times.
Other information
Orthographic note
Sometimes mispelled as Grimmia plagiopoda.
NVS code
The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.
GRIPLA
Previous conservation statuses
This is the first complete assessment of all known species of mosses found in the wild in Aotearoa New Zealand with a total of 560 species being assessed. The conservation status of mosses, published in the NZTCS database, replaces all previous assessments of mosses. Data supporting the 2025 NZTCS assessment of mosses has been published on the NZTCS database at https://nztcs.org.nz/reports/1155.
Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2014 | Threatened – Nationally Critical | Qualifiers: OL, TO
2010 | Threatened – Nationally Critical | Qualifiers: OL, TO
2005 | Threatened – Nationally Critical | Qualifiers: TO
Referencing and citations
References and further reading
Sainsbury, G.O.K. 1955: A handbook of the New Zealand mosses. Royal Society of New Zealand Bulletin 5.
Seppelt, R.D.; Green, T.G.A. 1998: A bryophyte flora for Southern Victoria Land, Antarctica. New Zealand Journal of Botany 36: 617-635.
Attribution
Factsheet Prepared for NZPCN by P.J. de Lange (29 August 2011). Description adapted from Sainsbury (1955).