Epilobium cockayneanum
Common names
willowherb
Biostatus
Native – Endemic taxon
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2023 | At Risk – Naturally Uncommon | Qualifiers: Sp, CR, DPR, DPS, DPT
Category
Vascular
Structural class
Herbs - Dicotyledons other than Composites
Simplified description
A poorly known species, easily mistaken for other similar Epilobium species, but with a fairly small distributional range. Charcterised by its creeping much branched tufted habit, with close set broadly ovate, ovate-elliptic to ovate-oblong, distinctly and obviously toothed leaves, and brown capsules.
Flower colours
White
Detailed description
Tufted perennial herb. Stems numerous, close set, initially decumbent, then ascending and/or erect, 100–250 mm long, pale green or reddish, indumentum bifariously to uniformly pubescent, glabrescent. Leaves opposite, crowded or widely spaced and approximate in lower part of stem, alternate within inflorescence, subsessile or petiolate with petioles less than or equal to 1 mm long; lamina 5–14 × 3–8 mm, green, dark green or reddish green (sometimes red-brown), broadly ovate to ovate-elliptic or ovate-oblong, membranous, glabrous, margins irregularly, often widely and obscurely toothed. Flowers erect, ± 4–6 mm diameter; sepals lanceolate; petals white or rose-pink, usually ± 2× length of sepals. Capsules 25–50 mm long, brown, glabrous or sparsely, mintely puberulent and then glabrate; pedicels 20–40 mm long, red-brown or reddish, minutely puberulent.
Similar taxa
Epilobium cockayneanum was merged with E. atriplicifolium into E. alsinoides as E. alsinoides subsp. atriplicifolium by Raven & Raven (1976). Here E. atriplicifolium is treated as a distinct species with which E. cockayneanum is most closely allied. Epilobium cockayneanum differs from E. atriplicifolium by its close-set, much branched, tightly matted, tufted growth habit; leaves which are more deeply toothed and broadly ovate, ovate-elliptic to ovate-oblong rather than weakly toothed and narrowly elliptic to linear leaves and 5–14 × 6–8 mm cf. 8–18 × 4–5 mm in E. atriplicifolium. Epilobium cockayneanum is virtually confined to the higher elevation sites of the North Island but it is widely sympatric with E. atriplicifolium and E. tenuipes in the South Island, and less frequently with E. alsinoides and E. atriplicifolium in the North Island, where as Raven & Raven (1976) note, these taxa “are sharply distinct”.
Distribution
Endemic. New Zealand: North Island (from southern Ruahine Ranges south), South Island (Marlborough and northern Canterbury). Mostly easterly.
Habitat
Montane to alpine in grassland and herbfield. preferring open ground.
Detailed taxonomy
Genus
Family
Synonyms
Epilobium cockaynianum Petrie (orthographic variant)
Taxonomic notes
Raven & Raven (1976) treated Epilobium cockayneanum as part of their concept of E. alsinoides subsp. atriplicifolium (A.Cunn.) P.H.Raven et Engelhorn. This concept is not followed here where E. alsinoides A.Cunn, E. atriplicifolium A.Cunn, E. elegans Petrie, and E. tenuipes Hook.f. are all regarded as species. This follows on from the extensive field work, and mostly unpublished opinions of the late A.P. (Tony) Druce who studied New Zealand epilobia extensively in the field and in cultivation. Although Raven & Raven (1976) had adopted an understandably broad concept of E. alsinoides, they had failed to recognize that those species allied to it or segregated from it retained their morphological and ecological distinctions and, aside from disturbed areas where hybridisation between them was sometimes common, they remained stable “units” elsewhere. Elsewhere in their treatment, Raven & Raven (1976) accepted at species rank other epilobia which also frequently hybridize, sometimes forming complex introgressive swarms in sites of prolonged human-induced disturbance, suggesting that their treatment of E. alsinioides and its allies was somewhat contradictory. That said, it should be noted that the treatment offered here is based entirely on the work of Druce (Druce 1993), which is mostly unpublished, and that, as a whole, New Zealand’s indigenous epilobia are still in need of a critical taxonomic review, ideally using DNA based methodologies from which to develop a sound framework.
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
November–March
Fruiting
November–May
Life cycle and dispersal
Minute pappate seeds are wind dispersed (Thorsen et al., 2009).
Propagation technique
Easily grown from fresh seed and rooted pieces. Susceptible to powdery mildew in humid climates. Otherwise inclined to become weedy.
Other information
Etymology
epilobium: From the Greek epi- ‘upon’ and lobos ‘a pod’, the flowers appearing to be growing on the seed pod.
cockayneanum: Named after Leonard Cockayne FRS (7 April 1855 - 8 July 1934) who is regarded as New Zealand’s greatest botanist and a founder of modern science in New Zealand
NVS code
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.
EPICOC
Chromosome number
2n = 36
Previous conservation statuses
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2017 | Data Deficient
2012 | Data Deficient
2009 | Not Threatened
2004 | Not Threatened
Regional conservation statuses
Otago: 2025 | Regionally Data Deficient
The regional threat classification system leverages off the national assessments in the NZTCS, providing information relevant for the regional context. Otago conservation status information is sourced from the “Conservation Status of Indigenous Vascular Plants in Otago, 2025” Jarvie S et al. (2025) report.
Referencing and citations
References and further reading
Allan HH. 1961. Flora of New Zealand, Volume I. Indigenous Tracheophyta: Psilopsida, Lycopsida, Filicopsida, Gymnospermae, Dicotyledones. Government Printer, Wellington, NZ. 1085 p.
Druce AP. 1993. Indigenous vascular plants of New Zealand. Ninth Revision. Unpublished Checklist held at Landcare Research, Lincoln, New Zealand.
Raven PH, Raven TE. 1976. The genus Epilobium in Australasia. New Zealand DSIR Bulletin 216. Government Printer, Wellington, NZ. 321 p.
Thorsen MJ, Dickinson KJM, Seddon PJ. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 11: 285–309. https://doi.org/10.1016/j.ppees.2009.06.001.
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange 1 September 2011. Description adapted from Allan (1961).
Some of this factsheet information is derived from Flora of New Zealand Online and is used under a Creative Commons Attribution 3.0 New Zealand licence.