Bryum tenuidens


Bryum: From the Greek word bryon meaning 'lichen' or 'moss'.

Common Name(s)


Current Conservation Status

2009 - Data Deficient

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


2009 - OL


Bryum tenuidens Dixon et Sainsbury



Flora Category

Non Vascular - Native




Endemic. New Zealand: South Island (Kahurangi National Park, Arthur Range)


Synoicous, minute, densely tufted and matted terricolous moss. Plants yellowish-green above, light brown below. Mats held together at base by radicles. Stems 5.0-7.5 mm tall, simple or sparingly branched. Leaves about 2 mm long, either in dense comose tufts or rather regularly paced on the stem, erect and appressed both dry and moist, vinous red at the wide base, oblong, acuminate; margins plane, entire or faintly and bluntly notched towards the apex. Nerve strong, about 60 microns wide at the base, excurrent in a rather long, rigid, slightly denticulate point. Upper cells laxly rhomboid-hexagonal, 50-80 microns long and 3-5 x 1; cells towards the base becoming shortly rectangular; those at the margin in 2-3 rows narrowly linear, forming a rather distinct border. Seta 10-18 mm long, flexuose, reddish, arcuate at the apex. Capsule 2.0-2.5 mm long, pendulous, symmetrical, clavate or sometimes pyriform, narrowed at the mouth, light-brown with a darker tapered neck; annulus well developed. Exothecial cells large, subisodiametrical, with sinuose walls. Peristome teeth thin and short (300 microns long), distant, narrowly lanceolate-subulate, pale yellow below, margined, finely papillose on the dorsal face and with a zigzag median line; ventral lamellae weakly developed and only slightly projecting; inner peristome pale; basal membrane low, variably adherent; processes almost equaling the teeth, hyaline, widely gaping on the median line. Cilia one to each process, very short and rudimentary, neither nodose or appendiculate. Operculum conical, mamillate. Male plants separate, shorter, bearing terminal flowers.


Although fruit has been seen insufficient information exists to provide any details on the timing of fruiting


Bryum tenuidens is known only from a single gathering made from Mt Arthur in 1930 (Glenny et al. 2011). It has not been seen there since although it is difficult to see what threatens, nor why it should be so uncommon. Possibly it is vulnerable to trampling by humans as where it was found is now a popular walking track.

Endemic Taxon


Endemic Genus


Endemic Family



Fact sheet prepared for NZPCN by P.J. de Lange (1 October 2007).Description adapted from Sainsbury (1955).

References and further reading

Glenny, D.; Fife, A.J.; Brownsey, P.J.; Renner, M.A.M.; Braggins, J.E.; Beever, J.E.; Hitchmough, R. 2011: Threatened and uncommon bryophytes of New Zealand (2010 Revision). New Zealand Journal of Botany 49: 305-327.

Sainsbury, G.O.K. 1955: A handbook of the New Zealand mosses. Royal Society of New Zealand Bulletin 5.

This page last updated on 27 Aug 2013