Species
Epilobium alsinoides
Etymology
Epilobium: From the Greek epi- 'upon' and lobos 'a pod', the flowers appearing to be growing on the seed pod.
alsinoides: like chickweed
Common Name(s)
willowherb
Current Conservation Status
2012 - Not Threatened
Conservation status of New Zealand indigenous vascular plants, 2012
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2012 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2009 and replaces all previous NZTCS lists for vascular plants. Authors: Peter J. de Lange, Jeremy R. Rolfe, Paul D. Champion, Shannel P. Courtney, Peter B. Heenan, John W. Barkla, Ewen K. Cameron, David A. Norton and Rodney A. Hitchmough. File size: 792KB
Previous Conservation Status
2009 - Not Threatened
2004 - Not Threatened
Authority
Epilobium alsinoides A.Cunn.
Family
Onagraceae
Flora Category
Vascular - Native
EPIALS
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.
Structural Class
Dicotyledonous Herbs other than Composites
Synonyms
Epilobium alsinoides A.Cunn. subsp. alsinoides
Distribution
Endemic. New Zealand: North and South Islands (scarce in East Coast of the North Island, and apparently absent in the South Island, south of Nelson and northern Marlborough).
Habitat
Sea level to alpine. Usually in open grassland or on partially shaded, seasonally damp eroding banks
Features
Delicate, decumbent, matted, much-branched perennial herb up to 200 mm tall, bearing numerous leafy stolons arising from the base; plants densely strigulose-pubescent, hairs usually antrorsely appressed. Leaves on distinct petioles 1-2 mm long, opposite, alternate in the inflorescence, dull bluish-green, occasionally with a few hairs near the base on the margins, the lateral veins not prominent, 2-3 on each side of the midrib; lamina shorter than subtending internodes, 3.0-8.0 x 2.0-5.5 mm, ovate, with 2-4 indistinct teeth on each side (rarely entire), apex acute to obtuse, base rounded. Inflorescence erect, the flowers scattered down the stem. Flowers erect, Ovaries 6-15 mm long, densely strigulose, on pedicels 25-50 mm long. Floral tube 0.5-1.5 mm deep, 0.7-2.2 mm diameter, glabrous or strigulose externally. Sepals 2.0-4.5 x 0.8-1.5 mm, not keeled, glabrous or strigulose. Petals 2.8-6.0 x 1.8-4.5 mm, notch 0.7-2.0 mm deep; white, sometimes flushing pink after pollination. Anthers 0.4-0.9 x 0.25-0.5 mm, cream or yellow; filaments white, those of longer stamens 0.6-1.5 mm long, those of shorter stamens 0.3-0.8 mm long, the anthers of the longer stamens dehiscing first and shedding pollen directly on to the stigma after the flower opens. Style 1.0-1.7 mm high, white; stigma 1.0-1.5 x 0.4-0.65 mm, white, clavate, surrounded by anthers of at least the longer and usually both sets of stamens at anthesis. Capsule 25-30 mm long, on pedicels 10-60 mm long; blue-green, densely strigulose. Seeds 0.6-1.0 x 0.2-0.3 mm, pale orange-brown or orange, oblong-obovate, obovate, testa finely reticulate, apices rounded; coma 4.5-7.0 mm long, white, caducous.
Similar Taxa
Epilobium alsinoides differs from the allied E. atriplicifolium by having finely reticulate rather than papillose seeds, and pedicels which elongate to 10-80 mm (usually 20-80 mm long) long in fruiting specimens (10-90 mm but usually 10-40 mm in E. atriplicifolium). From E. tenuipes, E. alsinoides is separated by the ovate rather than narrowly elliptic or linear leaves, which are typically shorter than the internodes they subtend. In Epilobium tenuipes the mature capsules are usually conspicuously elevated above the leafy stems while they are much less so in E. alsinoides.
Flowering
November - January
Flower Colours
White
Fruiting
January - May
Propagation Technique
Easily grown from fresh seed and rooted pieces. Dislikes humidity and prone to powdery mildew in humid climates. Inclined to be weedy.
Threats
Not Threatened. However, E. alsinoides is seemingly scarce (apparently naturally so) north of the Waikato.
Chromosome No.
2n = 36
Endemic Taxon
Yes
Endemic Genus
No
Endemic Family
No
Notes on taxonomy
Raven & Raven (1976) adopted a very conservative treatment for New Zealand Epilobium. In that treatment they recognised Epilobium atriplicifolium and E. tenuipes as subspecies of E. alsinoides. They also included with E. alsinoides subsp. atriplicifolium, E. cockayneanum (treated as a species here) and within subsp. tenuipes they merged E. elegans (also accepted at species rank here). Raven & Raven (1976) argued for subspecies rank and species merger on the basis of what they saw as intergrading forms between E. atriplicifolium, E. cockayneanum, E. elegans and E. tenuipes in the South Island. They did note that intergrading was not evident in the North Island, where the "major entites...are sharply distinct" but they suggested that this had to do with the effectively autogamous breeding system of these taxa, and while they accepted that intergrading forms occurred within the most "highly disturbed vegetational formation in New Zealand" (i.e. tussock grasslands) suggesting that such intergrades were not natural, they nevertheless felt justified in their highly conservative treatment. Subsequently field botanists have largely followed the unpublished views of the late Tony Druce who continued to recognise as species E. atriplicifolium, E. cockayneanum, E. elegans and E. tenuipes. For want of a thorough, multi-marker DNA-based revision of New Zealand Epilobium, for now at least it seems preferrable to follow Druce (1993) rather than Raven & Raven (1976) whose treatment of Epilobium, whilst understandable for its time, seems inconsistent.
Fact Sheet Citation
Please cite as: de Lange, P.J. (Year at time of Access): Epilobium alsinoides Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. http://www.nzpcn.org.nz/flora_details.aspx?ID=1835 (Date website was queried)
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange (22 October 2012).Description adapted from Raven & Raven (1976)and Webb & Simpson (2001).
References and further reading
Druce, A.P. 1993: Indigenous vascular plants of New Zealand. Ninth Revision. Unpublished Checklist held at Landcare Research, Lincoln, New Zealand.
Raven, P.H.; Raven, T.E. 1976: The genus Epilobium in Australasia. New Zealand DSIR Bulletin 216. Wellington, Government Printer.
Webb, C.J.; Simpson, M.J.A. 2011: Seeds of New Zealand Gymnosperms and Dicotyledons. Christchurch, Manuka Press.
This page last updated on 3 Jan 2020