Species

Juncus acuminatus

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-fruited rush

Authority

Juncus acuminatus Michaux

Family

Juncaceae

Brief Description

Upright leafy rush to 80 cm tall, leaves round with internal cross walls (feels like clicks if you hold base of leaf between finger and thumb and slide up), plant reddish with branched flower heads made up of many clusters of 6 to 10 light brown flowers/capsules (fruit).

Flora Category

Vascular - Exotic

NVS Species Code

JUNACU

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

Common throughout the North Island and northern South Island, usually lowland.

Habitat

Margins of flowing and still water bodies, drains and wet pasture.

Features

Strictly erect tufted perennial, commonly reddish-tinged. Stems 30-80 cm high, distinctly septate internally just below inflorescence. Leaves terete or ± compressed with distinct transverse septa. Inflorescence very variable, 3-20 cm long, open, much-branched with 6-10-flowered clusters at ends of branches. Tepals 2.5-3.5 mm long, ± equal, narrow-lanceolate, stiff, acuminate. Stamens 3. Capsules 2.5-3.5 mm long, = or slightly > tepals, narrow, acute, shortly beaked, straw-coloured to brown.

Similar Taxa

Similar to other tubular septate leaved rushes, but only J. acuminatus and J. canadensis have septate stems beneath the inflorescence. J. canadensis has tailed seeds, larger capsules, is more densely upright and lacks the reddish tinged appearance.

Flowering

Spring to early summer

Flower Colours

Brown

Fruiting

Summer to autumn

Year Naturalised

1915

Origin

North and South 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 Ozophyllum (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.

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