Species

Juncus acutus

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)

sharp rush

Authority

Juncus acutus L.

Family

Juncaceae

Brief Description

Upright spiny rush to 1 m tall, with tall cylindrical sharp tipped, stems and leaves forming dense stiff clumps, with clumped flowerheads near the end of each stem, made up of many red-brown to orange flowers/capsules (fruit).

Flora Category

Vascular - Exotic

NVS Species Code

JUNACS

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.

Structural Class

Rushes and Allied Plants

Distribution

Scattered, but locally abundant in Northland, Auckland, Manawatu and Wellington, mostly coastal.

Habitat

Wet and seasonally dry sandy areas

Features

Very stout, forming dense prickly tufts; rhizomes stout, woody. Stems (40) -60-100cm × 1.5-5 mm, very stiff and erect, smooth, light green. Basal sheaths shining dark red-brown. Leaves 1-2, basal, terete, similar to stem, with very pungent tip. Inflorescence large, compact 5-15 cm long. Flowers crowded. Tepals c. 3 mm long, ± equal, very hard, outer mucronate, inner truncate to emarginate with wide membranous margin at tip. Stamens 6. Capsule 4.5-5 mm long, much > tepals, ovoid, abruptly tapered, acute, reddish-brown to brownish-orange. Seeds with distinct tails.

Similar Taxa

No other rush has a combination of leaves similar to the stem, sharp pointed and large (> 4 mm) red-brown to orange capsules in a dense clustered head.

Flowering

Summer

Flower Colours

Brown,Orange

Fruiting

Autumn

Year Naturalised

1923

Origin

Europe, Africa, North and South America

Reason for Introduction

Unknown, seed or soil contaminant.

Control Techniques

Can be controlled manually, mechanically or herbicidally depending on situation.

Life Cycle and Dispersal

Perennial. Seed dispersed by animals, water or contaminated machinery.

Notes on taxonomy

Subgenus Juncus, Section Juncus(Thalasii) 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