Epilobium nerteroides
Common names
willowherb
Biostatus
Native
Category
Vascular
Structural class
Herbs - Dicotyledons other than Composites
Flower colours
Violet/Purple, White
Detailed description
Loosely matted creeping perennial herb forming patches up to 0.4 m diameter; plants glabrous (rarely with a few strigulose hairs in lines decurrent from the margins of the petioles). Flowers arising individually from the leaf axils, the stems continuing to grow and root beyond the point where they are produced. Leaves opposite, dull pale to dark green, petioles distinct, 1-6 mm long; lateral veins of lamina (1-)2-3, on each side of the midrib, inconspicuous; lamina (3-)4-11 x (2-)0.3-0.8 mm, broadly elliptic to ovate, apex acute to obtuse, base rounded to acute, margins remotely serrulate or serrate, teeth (1-)2-8 on each side. Flowers erect. Ovaries (5-)8-13(-20) long, glabrous, green, borne on a glabrous pedicel (6-)9-19 mm long (the flowers usually falling before full pedicel elongation). Floral tube 5-11 x 11-15 mm. Sepals not keeled 1.0-3.1 x 0.7-1.1 mm, glabrous. Petals 2,5-5.3 x 1.5-4.0 mm, white, rarely pale pink, the notch 0.6-1.0 mm deep. Anthers 0.4-0.7 x 0.2-0.5 mm, yellow; filaments of the longer stamens 0.8-2.0 mm long, those of shorter ones 0.7-1.5 mm long, both sets shedding pollen directly on the stigma before or after the flower opens. Style 1.0-2.1 mm, white; stigma 0.7-1.5 x 0.4-0.9 mm, white, clavate, surrounded by anthers at anthesis. Capsules 15-42 mm long, glabrous, borne on pedicels (27-)35-90(-150) mm long. Seeds 0.6-0.9 mm long, orange-brown, oblong-elliptic, elliptic or obovate, finely reticulate-papillate; coma 4-6 mm long, white (sometimes tinged orange), caducous.
Similar taxa
Epilobium nerteroides is most likely to be confused with E. brunnescens, with which it often grows. Epilobium nerteroides is distinguished from E. brunnescens by its narrower leaves, more open growth habit; subglabrous stems and glabrous ovaries; and by the flowers which fall before the elongation of the pedicel has ceased. Raven & Raven (1976) note that E. nerteroides grows on shaded mossy rocks and stream banks while E. brunnescens prefers open gravel in stream beds and other distrubed places. However, in the Central North Island at least it is not that uncommon to find both species growing together.
Distribution
Endemic. New Zealand: North, South, Stewart and Chatham Islands.
Habitat
Coastal to subalpine. In riparian sites within forest and dense scrub growing on moss and liverwort encrusted rocks along watercourses.
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.
Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – these interim threat classification statuses has not been assessed by the NZTCS panel.
- 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
Onagraceae
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
September - March
Fruiting
November - May
Life cycle
Minute pappate seeds are wind dispersed (Thorsen et al., 2009).
Propagation technique
Easily grown from fresh seed and rooted pieces. Prefers a damp, shaded site. Inclined to be weedy.
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). If you have suggestions for the Wetland Indicator Status Rating, please contact: [Enable JavaScript to view protected content]
FAC: Facultative
Commonly occurs as either a hydrophyte or non-hydrophyte (non-wetlands).
Other information
Etymology
epilobium: From the Greek epi- ‘upon’ and lobos ‘a pod’, the flowers appearing to be growing on the seed pod.
nerteroides: Like Nertera, an unrelated plant
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.
EPINER
Chromosome number
2n = 36
Previous conservation statuses
2017 | Not Threatened
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Referencing and citations
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.
Attribution
Fact sheet prepared for NZPCN by: P.J. de Lange (28 October 2012). Description adapted from Raven & Raven (1976) and Webb & Simpson (2001)
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Epilobium nerteroides Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/epilobium-nerteroides/ (Date website was queried)