Juncus kraussii subsp. australiensis
Common name
sea rush
Synonyms
Juncus maritimus var. australiensis Buchenau
Family
Juncaceae
Flora category
Vascular – Native
Endemic taxon
No
Endemic genus
No
Endemic family
No
Structural class
Rushes & Allied Plants
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. 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.
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).
FACW: Facultative Wetland
Usually is a hydrophyte but occasionally found in uplands (non-wetlands).
Features
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.
Flowering
September - December
Flower colours
Brown, Red/Pink
Fruiting
November - April
Life cycle
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.
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. 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
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)