Epilobium microphyllum
Past favourite plant winner
Common names
willowherb
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Herbs - Dicotyledons other than Composites
Flower colours
White
Detailed description
Tufted, creeping herb with woody bases, and numerous ascending, wiry stems, (these branching from base) 120-150(-280) mm long. Stems purple-black or black (rarely pale brown), initially sprawling, bifariously pubescent, hairs, short ±. Leaves opposite, rarely alternate toward flowers, distant, on very short petioles; coriaceous, glabrous, adaxially; lamina usually broadly elliptic to rotund, rarely elliptic, sometimes oblong, ovate-oblong, ovate to obovate, 2-8 × 1-3 mm, dark green often with purple-red margins, abaxially usually purple-red, margins faintly denticulate or entire, apex mucronulate. Flowers 3-4 mm diameter; floral tube 0.4-0.6 mm deep, strigillose outside; petals white, 2.0-2.9 × 0.8-1.9 mm. Capsules with conspicuous bands of strigillose hairs along the lines of dehiscence, thus appearing striped light and dark, rarely strigillose all over, 0.9-2.2 cm long; fruiting pedicel 0.2-1.6 cm long. Seed smooth.
Similar taxa
Other Epilobium species; particularly E. brunnescens from which it is easily distinguished by the purple-black, ascending, wiry stems, and dark purple-black, silvery striped fruiting capsules.
Distribution
Endemic: New Zealand: North, South and Chatham Islands. From about Kawhia and East Cape south, locally abundant around the Cook Strait region, thence mainly easterly in the South Island.
Habitat
Gravelly or shingly riverbeds, flats and outwash plains; sea level to 1,200 m.
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 | Not Threatened
Detailed taxonomy
Family
Synonyms
Epilobium microphyllum var. prostratum Petrie
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
December - February
Fruiting
October - March
Life cycle and dispersal
Minute pappate seeds are wind dispersed (Thorsen et al., 2009).
Propagation technique
Easily grown from rooted pieces and fresh seed. An attractive plant for an open spot, a rock garden, or as a pot plant. Prone to powdery mildew in humid climates.
Other information
Where To Buy
Not Commercially available
Plant of the Month
This plant has been featured as a Plant of the Month – see Trilepidea: NZPCN newsletter for December 2007 for the full story.
Etymology
epilobium: From the Greek epi- ‘upon’ and lobos ‘a pod’, the flowers appearing to be growing on the seed pod.
microphyllum: Small leaf
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.
EPIMIC
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 | Not Threatened
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Regional conservation statuses
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 “Regional conservation status of indigenous vascular plants in Otago” Jarvie S et al. (2024) report.
Otago: 2024 | At Risk – Regionally Naturally Uncommon | Qualifiers: DPS, DPT, NStr, RR, Sp
Referencing and citations
References and further reading
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.
Attribution
Fact sheet prepared by P.J. de Lange for NZPCN (1 June 2013)
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Epilobium microphyllum Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/epilobium-microphyllum/ (Date website was queried)