Vascular – Exotic
Herbs - Dicotyledons other than Composites
2n = 36
Stout, rhizomatous herb with erect stems up to 2 m tall. All parts (except flowers) conspicuously hairy. Leaves lanceolate to narrowly oblong, coarsely toothed light green, green to grey-green. Flowers conspicous, up to 10 mm diameter, petals dark pink to rose-purple, stigma white, exserted.
Naturalised to New Zealand. As of 2019 only known from the South Island from wetlands in North Canterbury
Wetlands margins and damp ground in wasteland and urban areas.
Wetland plant indicator status rating
Information derived from the revised national wetland plant list prepared to assist councils in delineating and monitoring wetlands (Clarkson et al., 2021 Manaaki Whenua – Landcare Research Contract Report LC3975 for Hawke’s Bay Regional Council). The national plant list categorises plants by the extent to which they are found in wetlands and not ‘drylands’. The indicator status ratings are OBL (obligate wetland), FACW (facultative wetland), FAC (facultative), FACU (facultative upland), and UPL (obligate upland).
FACW: Facultative Wetland
Usually is a hydrophyte but occasionally found in uplands (non-wetlands).
Semi-aquatic, softly-hairy, rhizomatous, much branched herb up to 2 m tall. Stems erect, woody near base, densely, softly pubescent; hairs in admixtures of . non-glandular and eglandular. Leaves opposite to subopposite, 30‒60 ×10‒26 mm, light green, green to grey-green, surfaces densely, finely pubescent (hairs eglandular), lanceolate to narrowly oblong, bases clasping stem and slightly decurrent with stem, apices acute, margins coarsely to finely toothed in upper ⅔‒½. Infloresences borne in upper third of stem, with one flower per leaf axil. Flowers erect up to 10 mm diameter; ovaries erect or outwardly falcate, 30‒50 mm long, densely strigulose, dull green-green or maroon, borne on a pedicel 4‒20 mm long. Hypanthium 1.8–2.8 × 1.6–3.2 mm, bearing a conspicuous rim of white hairs near apex. Sepals 5–7.0 × 2.3–2.8 mm, grey-green to green, broadly lanceolate to obtuse, keeled, both surfaces softly pubescent. Petals 6–18.0 × 5.0–10.0 mm, dark pink to rose-purple, ovate, apically weakly to prominently notched. Styles white, exserted. Fruits 25‒100 mm long, pubescent, hairs glandular. Seeds c. 1mm long, surface coarsely papillose, comose.
Epilobium palladiflorum is superficially similar but is a smaller, sparingly branched plant up 1.4 m tall (usually less), with narrower lanceolate leaves, and whose stems and leaves are finely, sparsely hairy (not densely so). The inflorescences of Epilobium palladiflorum when in bud nodding rather than erect, while the flower petals are also mostly white, occasionally pale pink.
November - April
January - May
Perennial herb with wind dispersed seeds
Possibly Australia (where this species is also naturalised) or from Europe or North America.
Reason for introduction
Possibly illegally cultivated from which plants escaped, or possibly naturally dispersed from Australia (where it not indigenous).
epilobium: From the Greek epi- ‘upon’ and lobos ‘a pod’, the flowers appearing to be growing on the seed pod.
Description and fact sheet prepared by P.J. de Lange (10 June 2020). Description based on herbarium specimens.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Epilobium hirsutum Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/epilobium-hirsutum/ (Date website was queried)