Species

Cirsium palustre

Etymology

Cirsium: a kind of thistle
palustre: From the Latin palus 'swamp', meaning growing in swamps

Common Name(s)

marsh thistle

Authority

Cirsium palustre (L.) Scop.

Family

Asteraceae

Brief Description

Prickly thistle with cobwebby hairs over most parts, small magenta flowerheads in clusters of up to 10 at the tip of a thin ± leafless prickly flower stem, up to 1.5 m tall, easy to break.

Flora Category

Vascular - Exotic

NVS Species Code

CIRPAL

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

Dicotyledonous Herbs - Composites

Distribution

Scattered throughout both islands, absent from drier areas, common in Westland

Habitat

Wet pasture and swampy waste places.

Features

Fibrous rooted biennial. Stems not branched, or branched above, with soft scattered multicellular and fine cobwebby hairs, (20)-80-150-(200) cm tall, ribbed, with coarsely spiny wings between leaf bases; branches slender. Leaves oblanceolate to narrowly elliptic, shallowly to deeply pinnatifid, green above, paler beneath, (5)-10-25-(35) X (1.5)-3-8-(15) cm, with sparse soft multicellular hairs above and beneath, often also with sparse to dense cobwebby tomentum beneath; Leaf lobes narrowly deltoid to linear; prickles pale, 2-10 mm long; uppermost leaves becoming smaller. Capitula cylindric to narrowly ovoid at flowering, erect, 1.2-1.5X 1 cm, in clusters of up to 10; peduncles 0-1 cm long. Outer involucral bracts linear, ciliate; apex acute, not spinous, suberect. Carolla magenta, 11-12 mm long; lobes 3.5-4-(5) mm long. Style slightly exserted beyond carolla lobes. Achenes pale, narrowly obovoid, 3-3.5 X c. 1 mm; pappus 8-12 mm long; cilia on pappus bristles 1-2 mm long.

Similar Taxa

No other thistle has the combination of magenta flowerheads and slender, winged, brittle stems.

Flowering

November - to February

Flower Colours

Red / Pink,Violet / Purple

Fruiting

November-March-(May)

Year Naturalised

1911

Origin

Eurasia

Reason for Introduction

Unknown, seed or soil contaminant

Control Techniques

Can be controlled manually, or herbicidally depending on situation.

Life Cycle and Dispersal

Biennial. Seed dispersed by wind or contaminated machinery.



Attribution

Factsheet prepared by Paul Champion and Deborah Hofstra (NIWA). Features description from Webb et al., (1988).

References and further reading

Webb, C.J.; Sykes, W.R.; Garnock-Jones, P.J. (1988). Flora of New Zealand Volume 4: Naturalised pteridophytes, gymnosperms, dicotyledons. Botany Division, DSIR, Christchurch.

Popay et al (2010).  An illustrated guide to common weeds of New Zealand, third edition.  NZ Plant Protection Society Inc, 416pp.

Johnson PN, Brooke PA (1989).  Wetland plants in New Zealand.   DSIR Field Guide, DSIR Publishing, Wellington. 319pp.

This page last updated on 21 Aug 2013