Juncus edgariae
Common names
wiwi, Edgar’s rush
Biostatus
Native
Category
Vascular
Structural class
Rushes & Allied Plants
Detailed description
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).
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.
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – these interim threat classification statuses has not been assessed by the NZTCS panel.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2023 | Not Threatened
Detailed taxonomy
Family
Juncaceae
Synonyms
Juncus gregiflorus L.A.S.Johnson (now an Australian endemic), Agathryon edgariae (L.A.S. Johnson & K.L.Wilson) Záveská Drábková & Proćków
Taxonomic notes
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.
Proćków et al. (2023) proposed a taxonomic segregation of Juncus into six genera based on molecular and morphological evidence. Whilst it has long been recognised that the current circumscription of Juncus includes morphologically divergent taxa—reflected in the recognition of numerous subgenera and sections—the consensus view of the NZPCN website taxonomy subcommittee, taking into consideration advice from Australian Juncus expert Dr Karen Wilson (NSW Herbarium) and others in Europe is that the generic segregations proposed need further consideration and testing. Accordingly, it has been decided to maintain the current broad circumscription of Juncus, but to include all new names as synonyms in factsheets. We thank, in particular, Dr Wilson for her helpful comments.
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
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.
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). If you have suggestions for the Wetland Indicator Status Rating, please contact: [Enable JavaScript to view protected content]
FACW: Facultative Wetland
Usually is a hydrophyte but occasionally found in uplands (non-wetlands).
Other information
Cultivation
Occasionally available from retail plant and specialist native plant nurseries
Etymology
juncus: From the Latin jungere ‘to tie or bind’, the stems of some species being used to make cord (Johnson and Smith)
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
Previous conservation statuses
2017 | Not Threatened
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Referencing and citations
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.
Proćków, J., Záveská Drábková, L. 2023. A revision of the Juncaceae with delimitation of six new genera: nomenclatural changes in Juncus. Phytotaxa 622(1): 17–41.
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
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).
Some of this factsheet information is derived from Flora of New Zealand Online and is used under a Creative Commons Attribution 3.0 New Zealand licence.
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)