Vascular – Exotic
Herbs - Dicotyledonous composites
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.
Locally well established in South Taranaki and Wanganui District.
Wetlands and riparian margins of water bodies, particularly areas that are rich in Nitrogen.
Wetland plant indicator status rating
FACW: Facultative Wetland
Usually is a hydrophyte but occasionally found in uplands (non-wetlands).
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.
Not similar to other wetland plants with possible exception of Bidens spp. that lack hairs and have coarser toothed leaflets.
January - March
Red/Pink, Violet/Purple, White
Perennial. Produces thousands of tiny wind dispersed seeds. Also has the potential to spread by water and contaminated machinery, deliberate planting.
Eurasia, North West Africa
Reason for introduction
Not controlled in New Zealand.
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
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.