Eupatorium cannabinum


Eupatorium: Commemorating Mithridates Eupator, king of Pontus and Armenia Minor in northern Anatolia (now Turkey) from about 120–63 BC, who is said to have discovered one of the species as an antidote for poison.
cannabinum: Like Cannabis, hemp

Common Name(s)

hemp agrimony


Eupatorium cannabinum L.



Brief Description

Tall upright herb with downy hairy branches up to 2 m tall, leaves in pairs, stalked and divided into 3 segments, each with toothed edges, flowerheads a flat mass of small pink flowers on top of each stem.

Flora Category

Vascular - Exotic

Structural Class

Dicotyledonous Herbs - Composites


Locally well established in South Taranaki and Wanganui District.


Wetlands and riparian margins of water bodies, particularly areas that are rich in Nitrogen.


Perennial herb with a woody rootstock, shoots erect 0.3-2 m, simple or short branched, downy striate. Basal leaves oblanceolate, petiolate; cauline leaves subsessile, 3 (-5)-pinnate with elliptic-acuminate toothed pinnae 5-10 cm, short glandular-hairy. Inflorescence a dense terminal corymb, each head with 5-6 reddish-mauve to white florets, 1-2 mm diameter and c. 10 oblong purple-tipped involucral bracts c. 6 mm. Achenes blackish, 5-angled, gland dotted, pappus whitish.

Similar Taxa

Not similar to other wetland plants with possible exception of Bidens spp. that lack hairs and have coarser toothed leaflets.


January - March

Flower Colours

Red / Pink,Violet / Purple,White



Year Naturalised



Eurasia, North West Africa

Reason for Introduction

Ornamental plant

Control Techniques

Not controlled in New Zealand.

Life Cycle and Dispersal

Perennial. Produces thousands of tiny wind dispersed seeds. Also has the potential to spread by water and contaminated machinery, deliberate planting.


Factsheet prepared by Paul Champion and Deborah Hofstra (NIWA).

References and further reading

Clapham, A.R.; Tutin, T.G.; Warburg, E.F.  (1962). Flora of the British Isles.  Cambridge University Press, Second Edition.  1269pp.

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.

This page last updated on 21 Aug 2013