Species

Epilobium tenuipes

Etymology

Epilobium: From the Greek epi- 'upon' and lobos 'a pod', the flowers appearing to be growing on the seed pod.

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 tenuipes Hook.f.

Family

Onagraceae

Flora Category

Vascular - Native

NVS Species Code

EPITNU

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 confertifolium var. tenuipes (Hook.f.) Hook.f.; Epilobium nanum Colenso; Epilobium alsinoides subsp. tenuipes (Hook.f.) Raven et Engelhorn

Distribution

Endemic. New Zealand: North (Central and Southern North Island), South Island (throughout)

Habitat

Montane to alpine in tussock grassland, shrubland (especially grey scrub), on rubble slopes and slip scars in subalpine scrub.

Features

Erect open, creeping perennial herb 10-120 mm tall, base usually bearing sparse leafy stolons otherwise much branched; plants with broad strigulose lines decurrent from petiole margins, or strigulose all round near stem base, hairs appressed, occasionally erect. Leaves on petioles 1-2 mm long, opposite, alternate in the inflorescence, dull bluish-green, reddish green to bronze green, the lateral veins not prominent, 0-4 on each side of the midrib; lamina 5-10 x 1-3 mm, narrowly elliptic to linear, apex acute base attenuate, margins serrulate (rarely entire), with 0-4 teeth on each side. Inflorescence erect, the flowers scattered down the stem. Flowers erect. Ovaries 6-15 mm long, glabrous (or with broad strigulose lines of hairs running up sutures), on pedicels 3-27 mm long, these densely strigulose all around (pubescence extending to base of capsule thence stopping abruptly, very rarely with a few minute hairs on abaxial floral tube). 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. Petals 2.8-3.0 x 1.8-2.2 mm, notch 0.3-0.7 mm deep; white. Anthers 0.4-0.9 x 0.25-0.5 mm, cream or yellow; filaments white, those of longer stamens 1-2 mm long, those of shorter stamens 0.5-1.5 mm long, the anthers of the longer stamens dehiscing first and shedding pollen directly on to the stigma after the flower opens. Styles 1.2-1.8 mm high, white; stigma 1.0-2.0 x 0.3-1.0 mm, white, clavate, surrounded by anthers of at least the longer and usually both sets of stamens at anthesis. Capsule 15-25 mm long, on greaty elongated pedicels 20-100 mm long (usually held well above subtending foliage); blue-green or reddish, glabrous to finely puberulent. Seeds 0.8-1.1 x 0.3-0.5 mm, pale orange-brown to orange, obovoid or narrowly obovoid, testa finely reticulate, apex distinctly, though narrowly, truncately beaked; coma 5-7 mm long, white caducous.

Similar Taxa

As Raven & Raven (1976) argued, E. tenuipes, E. atriplicifolium and E. alsinoides are closely allied. E. alsinoides is separated from E. tenuipes 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. E. atriplicifolium differs from E. tenuipes by having finely reticulate-papillate rather than finely reticulate seeds, and pedicels which elongate to 10-90 mm (usually 10-40 mm long) long in fruiting specimens (10-80 mm but usually 20-80 mm in E. alsinoides). Epilobium elegans was merged with E. tenuipes (as E. alsinoides subsp. tenuipes) by Raven & Raven (1976) it differs from E. tenuipes by its longer (10-20 mm cf. 5-10 mm in E. tenuipes), slightly broader (2-4 mm cf. 1-3 mm in E. tenuipes) leaves, larger flowers (up to 8 mm diameter in E. elegans, up to 4 mm diameter in E. tenuipes), glabrous rather glabrous to finely puberulent longer capsules (20-30 mm cf. 15-25 mm long in E. tenuipes) and consistently smooth rather smooth or minutely reticulate seeds

Flowering

November - March

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

Chromosome No.

2n = 36

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

Life Cycle and Dispersal

Minute pappate seeds are wind dispersed (Thorsen et al., 2009).


Where To Buy

Not commercially available

Taxonomic Notes

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) they nevertheless felt justified in their highly conservative treatment. Subsequently field botanists following the views of the late Tony Druce have continued to recognise as species E. atriplicifolium, E. cockayneanum, E. elegans and E. tenuipes. For want of a thorough, 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.

Attribution

Fact sheet prepared for NZPCN by P.J. de Lange (22 October 2012). Description adapted from Raven & Raven (1976).

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.

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.

This page last updated on 22 Sep 2014