Danthonia nuda Hook.f., Notodanthonia nuda (Hook.f.) Zotov
Vascular – Native
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.
2n = 24
Current conservation status
The threat classification status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2017 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants. Authors: By Peter J. de Lange, Jeremy R. Rolfe, John W. Barkla, Shannel P. Courtney, Paul D. Champion, Leon R. Perrie, Sarah M. Beadel, Kerry A. Ford, Ilse Breitwieser, Ines Schönberger, Rowan Hindmarsh-Walls, Peter B. Heenan and Kate Ladley. Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – a suggested threat classification status has not been assessed by the NZTCS panel.
2017 | At Risk – Naturally Uncommon | Qualifiers: RR
Previous conservation statuses
2012 | At Risk – Naturally Uncommon | Qualifiers: RR
2009 | At Risk – Naturally Uncommon | Qualifiers: DP, RR
2004 | Range Restricted
Endemic. North Island, Central Volcanic Plateau (Mt Ruapehu), Ruahine and Tararua Ranges.
Subalpine to alpine in flushes and bogs.
Wetland plant indicator status rating
Information derived from the revised national wetland plant list prepared to assist councils in delineating and monitoring wetlands (Clarkson et al., 2021 Manaaki Whenua – Landcare Research Contract Report LC3975 for Hawke’s Bay Regional Council). The national plant list categorises plants by the extent to which they are found in wetlands and not ‘drylands’. The indicator status ratings are OBL (obligate wetland), FACW (facultative wetland), FAC (facultative), FACU (facultative upland), and UPL (obligate upland).
OBL: Obligate Wetland
Almost always is a hydrophyte, rarely in uplands (non-wetlands).
Diminutive, diffuse tufted grass, leafy at ends of elongating shoots, rooting at nodes; leaves somewhat acute, more or less equal to culms, dis-articulating at ligule. branching intravaginal. Leaf-sheath pale straw-coloured to light grey, glabrous; apical tuft of hairs few, 1-2 mm long. ligule to 0.4 mm. Leaf-blade to 80 mm, folded, narrow, rather soft, glabrous. Culm to 100 mm, internodes glabrous. Panicle small, erect, to 30 mm, of few spikelets on short pedicels; rachis and pedicels slender, closely short-scabrid and some longer hairs at branch axils. Spikelets usually 3-flowered, awns barely exserted from glumes. Glumes purplish centrally, ovate, obtuse, more or less equal, 3.5-7.0 mm long; lower 3-5-nerved, upper 3-nerved. Lemma 2.3-3.5 mm, 5-9-nerved, upper and lower rows of hairs very sparse, upper row usually of small marginal tufts with a few scattered hairs, elsewhere glabrous, margins with scattered hairs; lobes 0.2-0.5 mm, acute to acuminate, not awn-tipped; central awn 1-2 mm long, erect, column scarcely evident. Palea 2.4-2.8 mm long, reaching base of awn, sinus, = upper lemma hairs, inter keel glabrous, margins occasionally with a few long hairs. Callus c.0.3 mm long, a few marginal hairs not reaching lower lemma hairs, or marginal tufts denser, slightly overlapping lower lemma tufts. Rachilla 0.5-0.8 mm. Anthers 0.7-0.8. Seed not seen.
Manaaki Whenua Online Interactive Key
Recognised by the awn of the lemma 1-2 mm long, and the lemma which is 2.3-3.5 mm, 5-9-nerved, with the upper and lower rows of hairs very sparse, and the upper row usually comprised of small marginal tufts with a few scattered hairs, otherwise glabrous. The lemma margins have scattered hair and lobes 0.2-0.5 mm, which are acute to acuminate. Its relationship to the other indigenous species is not clear though it seems closest to R. australe and R. pumilum. The small, few-flowered spikelets and absence of seed are useful field characters.
November - January
Grows easily enough from the division of whole plants
A very local endemic, rarely collected.
rytidosperma: Wrinkled seed
Where To Buy
Not commercially available.
Some botanists believe that this uncommon species is a naturally occurring, uncommon, sterile hybrid (B.P.J. Molloy pers. comm.; de Lange et al. 2009; de Lange & Rolfe 2010), especially as the seed of this species has never been seen. However, the recent (2012) discovery of this species growing in abundance in alpine flushes on Mt Ruapehu (P.J. de Lange, N.J. Singers, J.R. Rolfe & M.A.M. Renner unpubl. data), in morphologically uniform populations suggests that it is a functional species. Currently this species is listed as Taxonomically Indistinct in Appendix 3 of de Lange et al. (2009) having previously been listed as “Range Restricted” by de Lange et al. (2004). Clearly this status will need to change and as as an interim measure the status of “At Risk / Naturally Uncommon” appended DP [Data Poor], RR [Range Restricted] is here suggested (P.J. de Lange unpubl. data).
Fact sheet prepared for NZPCN by P.J. de Lange 30 August 2006. Description adapted from Edgar & Connor (2000).
References and further reading
de Lange, P.J.; Norton, D.A.; Heenan, P.B.; Courtney, S.P.; Molloy, B.P.J.; Ogle, C.C.; Rance, B.D.; Johnson, P.N.; Hitchmough, R. 2004: Threatened and uncommon plants of New Zealand. New Zealand Journal of Botany 42: 45-76.
de Lange, P.J.; Norton, D.A.; Courtney, S.P.; Heenan, P.B.; Barkla, J.W.; Cameron, E.K.; Hitchmough, R.; Townsend, A.J. 2009: Threatened and uncommon plants of New Zealand (2008 revision). New Zealand Journal of Botany 47: 61–96.
de Lange, P.J.; Rolfe, J.R. 2010: New Zealand Indigenous Vascular Plant Checklist. Wellington, New Zealand Plant Conservation Network. 164pp.
Edgar, E.; Connor, H.E. 2000: Flora of New Zealand. Vol. V. Grasses. Christchurch, Manaaki Whenua Press. 650 pp.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Rytidosperma nudum Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/rytidosperma-nudum/ (Date website was queried)