Juncus effusus var. effusus
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.
Upright clump-forming leafless rush to 1.2 tall, with tall, soft*, cylindrical stems, with continuous pith. The open clustered flowerheads near the end of each stem are made up of many light brown flowers/capsules (fruit). *Stems squash much more easily between thumb and fingers than most other ‘leafless’ rushes.
Widespread and common throughout.
Wet pasture and a wide range of wet habitats, including peaty areas.
Dense tuft-forming rush with short rhizomes. Stems 30-120 cm x 1.5-3 mm, cylindrical, bright or yellow-green, softer than most similar spp, easily split or compressed, smooth, shining; with continuous, cobwebby pith. No true leaves, only reddish-brown basal sheaths, closely held to stem. Seedhead not at end of stem, with many tiny green flowers along short, downward-curving branchlets. Seed capsule 2-3 mm long, oval, light brown.
Similar to other tall leafless rushes, but has an open inflorescence with the lower branches decumbent and cobwebby continuous pith in the stem. The soft, easily compressed and broken stems are distinct.
Spring to early summer
Summer to autumn
Seed dispersed by animals, water or contaminated machinery.
Europe, Asia and Africa
Reason for introduction
Unknown, seed or soil contaminant.
Rarely controlled, but can be controlled manually, mechanically or herbicidally depending on situation, susceptible to grazing.
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 Agathyron, Section Juncotypus (Genuini) Kirschner (2002: Juncaceae 3)
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
Kirschner, J. (compiler) (2002). Juncaceae 3: Juncus subg. Agathryon, Species Plantarum: Flora of the World Part 8: 1-192.
Healy, A.J. (1982). Identification of weeds and clovers. New Zealand Weed and Pest Control Society Publication. Editorial Services Limited, Featherston. 299pp.