Juncus usitatus
Synonyms
None (first described in 1963)
Family
Juncaceae
Flora category
Vascular – Native
Endemic taxon
No
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.
JUNUSI
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.
Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2017 | Not Threatened | Qualifiers: SO
Previous conservation statuses
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Distribution
Indigenous. Kermadec, North, South, and Chatham Islands. Mainly northern but extending to about Canterbury. Also in Australia, Norfolk Island and New Caledonia
Habitat
Coastal to lowland. Often on offshore islands. Usually in open ground or shrubland, more rarely under tall forest. Evidentally preferring seasonally dry clay soils or growing amongst rock. Preferring sunny situations. A common urban weed in Auckland City, where it often grows on exposures of basalt lava.
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).
Features
Densely tufted, clump-forming, erect, slender, wiry, bright green to dark green perennial herb. Rhizome 2-3 mm diameter, horizontal. Flowering stems 0.5-1.2 m tall, 1-1.5 mm diameter, slender, finely ridged, not shining, light yellow-green, bright green to dark green, pith interrupted by numerous, irregular shaped lacunae or continuous. Leaves absent. Basal bracts short, closely appressed to the stem, lower bracts light grey, the upper bracts light brown, paler towards the apices. Inflorescence lateral, many-flowered, open and spreading, branchlets slender, curved, never clustered. Flowers 1.5-2.0 mm long, evenly spaced along inflorescence branchlets; tepals up to 2 mm long, initially pale green with very broad membranous margin, drying straw-yellow or pale brown. Stamens 3. Capsule 1.5-.20 mm long, more or less equal, equal or slightly greater than tepals, trigonous-spherical to almost globose, shining, pale straw-coloured or light brown.
Similar taxa
The thin, wiry, usually bright-green stems, and widely and evenly spaced flower/capsules on long spreading branchlets are diagnostic for this species. It could only be confused with the introduced J. subsecundus N.A.Wakef. which differs by the blue-green stems and capsules which are consistently > 2 (rather than < 2) mm long.
Flowering
October - April
Flower colours
Green, Yellow
Fruiting
October - September
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. Ideal for a sunny, seasonally damp clay soil.
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
Not commercially available
Attribution
Fact Sheet prepared for NZPCN by P.J. de Lange (1 September 2006). Description based on Moore & Edgar (1970).
References and further reading
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 usitatus Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/juncus-usitatus/ (Date website was queried)