Epilobium gunnianum
Common name
Gunn’s willowherb
Synonyms
Epilobium diversifolium Hausskn., Epilobium erosum Hausskn.
Family
Onagraceae
Flora category
Vascular – Native
Endemic taxon
No
Endemic genus
No
Endemic family
No
Structural class
Herbs - Dicotyledons other than Composites
Chromosome number
2n = 36
Current conservation status
The threat classification status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2017 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants. Authors: By Peter J. de Lange, Jeremy R. Rolfe, John W. Barkla, Shannel P. Courtney, Paul D. Champion, Leon R. Perrie, Sarah M. Beadel, Kerry A. Ford, Ilse Breitwieser, Ines Schönberger, Rowan Hindmarsh-Walls, Peter B. Heenan and Kate Ladley. Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – a suggested threat classification status has not been assessed by the NZTCS panel.
Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2017 | Non-resident Native – Vagrant | Qualifiers: SO
Previous conservation statuses
2012 | Non-resident Native – Vagrant | Qualifiers: SO
2009 | Non-resident Native – Vagrant | Qualifiers: SO
2004 | Non-resident Native – Coloniser
Distribution
Indigenous. In New Zealand known only from the South Island at Maungarakau Swamp, north-west Nelson, and from swamps near Wesport and Cape Foulwind. Also in Australia where it is common from southeastern Queensland south to Victoria and Tasmania.
Habitat
Coastal or lowland (0-30 m a.s.l.), where it inhabits moderately fertile to mesic wetlands dominated by raupo (Typha orientalis C.Presl), sedges and sphagnum moss.
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).
OBL: Obligate Wetland
Almost always is a hydrophyte, rarely in uplands (non-wetlands).
Features
Erect perennial herb forming bushy masses up to 0.8 m tall. Plants often heavily branched right from base, with the basal stock producing numerous leafy stolons. Stems completely covered in strigose hairs, with elevated lines decurrent from the petiole margins, especially within the inflorescence. Petiole 1-3 mm long. Leaves initially opposite becoming subalternate and then alternmate within the inflorescence; glabrescent to glabrous with midvein, basal margins usually finely strigulose; rarely leaves completely strigulose hairy; lamina 10-60 x 2-20 mm, dull green to grey-green or bright green, narrowly elliptic or elliptic, rarely lanceolate or narrowly ovate, apex obtuse to subacute, base subcordate to acute; lamina margins usually undulating, serrulate or erose-denticulate with up to 40 teeth; lateral veins prominent, usually 4-6 on each side of midrib. Inflorescence and flowers erect.
Similar taxa
Best distinguished from other wetland inhabiting epilobia by the seeds which have a distinct pale rim - unique to this species in New Zealand. it could be confused with E. pallidiflorum A.Cunn., but that species has narrower lanceolate leaves and more usually white rather than pink flowers, and the seeds are without rims.
Flowering
December - March
Flower colours
Red/Pink, Violet/Purple
Fruiting
January - April
Life cycle
Minute pappate seeds are wind dispersed (Thorsen et al., 2009).
Propagation technique
Easily grown from fresh seed and rooted pieces. Inclined to become invasive.
Threats
Unknown. First recorded from New Zealand in 1976 based on gatherings made as early as 1953. Its exact status is not clear though it has been confirmed as present in the Maungarakau Swamp at least as recently as 2000. In the Westport area many of the swamps it was recorded from have been destroyed but it was also found growing in drainage ditches, drains and channels near Cape Foulwind. It probably survives in that area and has simply been overlooked. It is not a big plant and being a somewhat weedy species it is easily overlooked or mistaken for a naturalised Epilobium. Abundant in Australia.
Etymology
epilobium: From the Greek epi- ‘upon’ and lobos ‘a pod’, the flowers appearing to be growing on the seed pod.
Where To Buy
Not commercially available
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange 6 January 2008. Description adapted from Raven & Raven (1976) and Webb & Simpson (2001).
References and further reading
Raven, P.H.; Raven, T.E. 1976: The genus Epilobium in Australasia. New Zealand DSIR Bulletin 216. Wellington, Government Printer.
Thorsen, M. J.; Dickinson, K. J. M.; Seddon, P. J. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 11: 285-309
Webb, C.J.; Simpson, M.J.A. 2011: Seeds of New Zealand Gymnosperms and Dicotyledons. Christchurch, Manuka Press.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Epilobium gunnianum Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/epilobium-gunnianum/ (Date website was queried)