Juncus kraussii subsp. australiensis
Common names
sea rush
Biostatus
Native
Category
Vascular
Structural class
Rushes & Allied Plants
Flower colours
Brown, Red/Pink
Detailed description
Dense to loosely tufted, dark brown to brownish-black, perennial herb. Rhizome 5–8 mm diameter, horizontal sparingly branched. Flowering stems 0.3–1.2 m tall, 1.5–3.0 mm diameter, rather distant along rhizome, rigid, terete, light to dark yellow-brown, dark brown or brownish-black; internal pith continuous; basal bracts stiff, acute, red-brown, upper ones obviously larger, broader and mucronate. Leaves 1–2, terete, bright green, sheathing at base, similar to the stems but shorter. Inflorescence apparently lateral, open, irregularly-branched, branchlets numerous, rigid, almost equaling the pungent sheathing bract. Flowers 3 mm long, clustered at the branchlet apices; tepals rigidly stiff, red-brown, midrib green to light brown. Stamens 3 perfect, 3 aborted, rarely with 1 or more of the usually aborted inner ring functional; anthers twice as long as filaments. Capsule slightly > tepals, dark brown to almost black, ovoid, shining, mucronate.
Similar taxa
Most likely to be found growing with Juncus acutus L., an aggressive, introduced species with sharp-tipped bracts above the flower heads; J. kraussii differs in having open rather than densely compact inflorescence; flowers in small rather than large, compact clusters; and dark brown rather than red-brown capsules which are more or less equal to, rather than > in length to the tepals.
Distribution
Indigenous. North, South and Chatham Islands. From Te Paki to the Okarito in the west and Dunedin in the South. Inland in the North Island at Lake Rotorua, at Orakeikorako, and in the South Island at Mesopotamia, Rangitata River.
Habitat
Primarily coastal where it is found in salt marshes, brackish stream, lagoon and river margins, estuaries. Also inland around geothermal vents at Lake Rotorua and Orakeikorako, and inland at the headwaters of the Rangitata River.
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.
- 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 | Qualifiers: SO
Detailed taxonomy
Family
Synonyms
Juncus maritimus var. australiensis Buchenau
Endemic taxon
No
Endemic genus
No
Endemic family
No
Ecology
Flowering
September–December
Fruiting
November–April
Life cycle and dispersal
Mucilaginous seeds are dispersed by attachment, wind and water (Thorsen et al., 2009).
Propagation technique
Easily grown from fresh seed and division of whole plants. An attractive species ideal in rock gardens and one that should be used more widely in coastal plantings, especially bordering saltmarshes.
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
Where To Buy
Not commercially available
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.
JUNKSA
Previous conservation statuses
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.
- 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.
2017 | Not Threatened | Qualifiers: SO
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Regional conservation statuses
The regional threat classification system leverages off the national assessments in the NZTCS, providing information relevant for the regional context. Otago conservation status information is sourced from the “Regional conservation status of indigenous vascular plants in Otago” Jarvie S et al. (2024) report.
Otago: 2024 | Threatened – Regionally Endangered | Qualifiers: OL, RR, NR
Referencing and citations
References and further reading
Johnson, A. T.; 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. I. Government Printer, Wellington.
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).
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 kraussii subsp. australiensis Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/juncus-kraussii-subsp-australiensis/ (Date website was queried)