Species
Juncus ensifolius
Etymology
Juncus: From the Latin jungere 'to tie or bind', the stems of some species being used to make cord (Johnson and Smith)
Common Name(s)
iris-leaved rush
Authority
Juncus ensifolius Wickstrom
Family
Juncaceae
Brief Description
Leafy rush to 70 cm tall, leaves flattened an iris-like (sword-shaped), plant blue-green with 1 to 3 spherical flowerheads made up of many dark-brown to black flowers/capsules (fruit).
Flora Category
Vascular - Exotic
Structural Class
Rushes and Allied Plants
Distribution
Scattered and local from Bay of Plenty, Westland and Canterbury.
Habitat
Swampy roadsides and riverine wetlands.
Features
Loosely tufted or forming open colonies, less frequently densely tufted; rhizome slender, ± far-extending. Stems 15-70 cm high, laterally compressed, almost winged at lower nodes, cauline leaves 2-3. Leaves ensiform, ± curved, ± flat, blue-green, longitudinal and transverse septa visible externally, often incomplete. Inflorescence of 1-3 large, many-flowered, usually blackish, globose clusters, causing taller stems to incline. Tepals 2.5-3 mm long, all ± equal, acute to acuminate. Stamens 3-6. Capsule c. 3 mm long, > tepals, oblong, shortly mucronate, dark brown to black.
Similar Taxa
Only J. ensifolius and the native J. prismatocarpus have flattened multitubular septate leaves. J. ensifolius itends to be sward-forming and has 2-3 black globose flower clusters rather than the clumped plants with many-branched inflorescences green or pink flower clusters of J. prismatocarpus
Flowering
Summer
Flower Colours
Black,Brown
Fruiting
Autumn
Year Naturalised
1940
Origin
Western North America
Reason for Introduction
Unknown, seed or soil contaminant.
Control Techniques
Not controlled in New Zealand.
Life Cycle and Dispersal
Seed dispersed by animals, water or contaminated machinery.
Notes on taxonomy
Subgenus Juncus, Section Iridifolii (Septati) Kirschner (2002: Juncaceae 2)
Attribution
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.
This page last updated on 5 Jun 2014