Vascular – Exotic
Rushes & Allied Plants
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.
Low-growing leafy rush to 25 cm tall (more than this in aquatic plants), leaves very fine, usually swollen at the leaf base, submerged leaves are fine and thread-like, up to 1 m long, plant often reddish with branched flowerheads made up of many small clusters of 2 to 6 yellow-brown flowers/capsules (fruit), but often clusters of leaves can be found on these flowers.
Widespread and common throughout.
Mostly peaty sites in wet pastures, water body margins, drains and wetlands, sometimes submerged.
Wetland plant indicator status rating
OBL: Obligate Wetland
Almost always is a hydrophyte, rarely in uplands (non-wetlands).
Low-growing, variable perennial rush, 5-15 cm high, densely tufted or with prostrate rooting stems with leafy tufts at nodes, often mat-forming or submerged. Stems usually reddish-tinged, slender, swollen at base, rooting at nodes. Leaves tiny and bristle-like (narrow, grass-like on floating and submerged plants), with distinct hollow compartments separated by partitions. Seedhead terminal, variable, unbranched and few flowered or branched and open, occ with tufts of bristly leaves. Flowers tiny, green to brown. Seed capsules 2-3 mm long, yellowish-brown.
No other introduced rushes have the clumped filamentous leaves, swelling at the nodes, proliferous flower heads. In aquatic habitats the leaves are longer and more grass-like and may be confused with J. bufonis, but the stems swollen at the base and the septa (cross wall) visible in the leaves distinguish J. bulbosus from J. bufonis. The native Juncus novae-zelandiae is superficially similar but has black capsules and lacks the leafy proliferous heads.
Spring to early summer
Summer to autumn
Seed dispersed by animals, water or contaminated machinery.
Eurasia and North Africa
Reason for introduction
Unknown, seed or soil contaminant.
Rarely controlled, but can be controlled manually, mechanically or herbicidally depending on situation.
juncus: From the Latin jungere ‘to tie or bind’, the stems of some species being used to make cord (Johnson and Smith)
Notes on taxonomy
Subgenus Juncus, Section Ozophyllum (Septati) Kirschner (2002: Juncaceae 2)
Factsheet prepared by Paul Champion and Deborah Hofstra (NIWA). Features description from Healy and Edgar (1980).
References and further reading
Healy, A.J.; Edgar, E. (1980). Flora of New Zealand, Volume III. Adventive Cyperaceous, Petalous and Spathaceous Monocotyledons. Government Printer, Wellington. 220pp.
Johnson PN, Brooke PA (1989). Wetland plants in New Zealand. DSIR Field Guide, DSIR Publishing, Wellington. 319pp.
Johnson, A. T. and Smith, H. A (1986). Plant Names Simplified: Their pronunciation, derivation and meaning. Landsman Bookshop Ltd: Buckenhill, UK.
Champion et al (2012). Freshwater Pests of New Zealand. NIWA publication. http://www.niwa.co.nz/freshwater-and-estuaries/management-tools/identification-guides-and-fact-sheets/freshwater-pest-species
Healy, A.J. (1982). Identification of weeds and clovers. New Zealand Weed and Pest Control Society Publication. Editorial Services Limited, Featherston. 299pp.
Kirschner, J. (compiler) (2002). Juncaceae 2: Juncus subg. Juncus, Species Plantarum: Flora of the World Part 7: 1-336.