Juncus edgariae
Common name
wiwi, Edgar’s rush
Synonyms
Juncus gregiflorus L.A.S.Johnson (now an Australian endemic)
Family
Juncaceae
Flora category
Vascular – Native
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Structural class
Rushes & Allied Plants
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.
JUNEDG
Chromosome number
2n = 40
Current conservation status
The conservation 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). 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.
2012 | Not Threatened
Previous conservation statuses
2009 | Not Threatened
2004 | Not Threatened
Distribution
Endemic. Kermadec, North, South, Stewart and Chatham Islands. Naturalised in Britain
Habitat
Easily the most common indigenous species. Coastal to alpine (1600 m a.s.l.) but mainly coastal to montane. Usually in open shrubland, fringing wetlands, and in seasonally damp sites. Often found invading pasture and in urban areas.
Features
Bright to dark green, orange-green to red-green (drying glossy yellow-green) rather variable perennial forming compact to diffuse tussocks 0.6-2.5 m tall. Rhizome at or just below ground, 5 mm diameter, horizontal, difficult to pull from the soil. Flowering culms 1-3 mm diameter, erect, rather wiry (very hard when dry), smooth, shining; striations 22-60; internal culm pith interrupted irregularly or occasionally continuous; leaves absent; basal bracts dark red-brown below, straw-coloured above, tightly sheathing the stem or the upper-most loosely sheathing. Inflorescence apparently lateral, variable, either many or few-flowered, open with few to many branches bearing flowers in small clusters at the tips of branchlets, or condensed to a compact, central cluster with a few pedunculate side clusters, or a single spherical compact head wider than 10 mm. Flowers 1.5-2.0 mm long; tepals 6, brownish green, later becoming brown, acute to acuminate or mucronate; outer tepals 1.7-2.6 mm long, with fine hyaline margins, inner tepals slightly shorter with broad hyaline margins. Stamens 3, shorter than tepals; anthers 0.4-0.6 mm long < or equal in legnth to filaments. Capsule 1.5-2.3 mm long, equal to or < tepals, ellipsoid, obovoid, dark golden brown, with a dark brown, obtuse, almost retuse, apiculate tip. Seeds 0.4-0.6 mm long.
Similar taxa
Distinguished from the other indigenous species with the flowers usually clustered at the branchlet apices, by the capsules 1.5-2.3 mm long. Moore & Edgar (1970) describe the stems of this species as bright green but in practice it is more usually dark green, orange-green or red-green, usually drying glossy yellow-green. Within the Central Volcanic Plateau of the North Island plants ascribed to this species often have extremely condensed, compact inflorescences. Of those species naturalised to New Zealand, J. edgariae is perhaps most similar to J. continuus L.A.S.Johnson, still a relatively uncommon species of mainly Northland habitats, and from which it differs by the usually interrupted (rarely continuous) bright white, dense stem pith and capsules < or more or less equal in length to the tepals. Long confused with Juncus gregiflorus L.A.S.Johnson which is now regarded as endemic to Australia (Johnson & Wilson 2000).
Flowering
October - December
Fruiting
November - April
Life cycle
Mucilaginous seeds are dispersed by attachment, wind and water (Thorsen et al., 2009).
Propagation technique
Easy from fresh seed and by the division of whole plants. Can be invasive.
Etymology
juncus: From the Latin jungere ‘to tie or bind’, the stems of some species being used to make cord (Johnson and Smith)
Where To Buy
Occasionally available from retail plant and specialist native plant nurseries
Cultural Use/Importance
Plants referred to this species from the Central Volcanic Plateau and adjacent mountain ranges of the North Island have a densely clustered inflorescence, quite distinct from lowland forms and this is retained in cultivation. They may warrant taxonomic recognition.
Attribution
Fact Sheet prepared for NZPCN by P.J. de Lange (1 September 2006). Description based on Moore & Edgar (1970) (as J. gregiflorus) supplemented by notes taken from Johnson & Wilson (2000).
References and further reading
Johnson, L.A.S.; Wilson, K.L. 2000: Juncus edgariae (Juncaceae) - a new species from New Zealand. Telopea 9: 399-402,
Johnson, A. T. and Smith, H. A (1986). Plant Names Simplified: Their pronunciation, derivation and meaning. Landsman Bookshop Ltd: Buckenhill, UK.
Moore, L.B.; Edgar, E. 1970: Flora of New Zealand. Vol. II, Wellington, Government Printer.
Thorsen, M. J.; Dickinson, K. J. M.; Seddon, P. J. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 11: 285-309
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Juncus edgariae Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/juncus-edgariae/ (Date website was queried)