Myriophyllum pedunculatum subsp. novae-zelandiae
Vascular – Native
Herbs - Dicotyledons other than Composites
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.
2n = 28
Current conservation status
The threat classification status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2017 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants. Authors: By Peter J. de Lange, Jeremy R. Rolfe, John W. Barkla, Shannel P. Courtney, Paul D. Champion, Leon R. Perrie, Sarah M. Beadel, Kerry A. Ford, Ilse Breitwieser, Ines Schönberger, Rowan Hindmarsh-Walls, Peter B. Heenan and Kate Ladley. Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – a suggested threat classification status has not been assessed by the NZTCS panel.
2017 | Not Threatened
Previous conservation statuses
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Endemic. New Zealand: North, South, Stewart, Chatham Islands.
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).
OBL: Obligate Wetland
Almost always is a hydrophyte, rarely in uplands (non-wetlands).
Perennial mat-forming herb, aquatic to terrestrial, stems green, erect or prostrate, 20-100(-150) mm long, rooting at lower nodes, usually ± unbranched apart from rhizomatous portions at base. Leaves all entire, linear, 2-6 mm long, 0.5 mm wide, decussate, tip blunt to acute, sometimes almost acuminate, usually with a ± well defined midrib. Hydathodes 0-2. Inflorescence a terminal spike with the flowers borne singly in axils of the upper leaves which are indistinguishable from the other leaves. Each flower subtended by 2 bracteoles which are deltoid, 0.6-0.7(-1.3) × 0.2-0.3 mm, acuminate. Flowers unisexual, males and females often borne on separate stems, but if together, then males borne in upper axils, females below. Male flowers 4-merous, sessile or on pedicel up to 1 cm long. Sepals 4, oblanceolate, lanceolate to narrowly ovate or obovate, 0.9-1.4 × 0.3-0.5 mm, acute or obtuse, sometimes shortly mucronate, margins entire or minutely denticulate, Petals 4, red, hooded, weakly keeled, 1.3-1. 7(-2.5) × 0.8 mm, reflexed at anthesis. Stamens 8; filaments short, lengthening to 2.5 mm at anthesis; anthers linear-oblong, 0.9-1.1(-1.6) × 0.4 mm, 4-locular, shortly apiculate. Styles and ovary 0. Female flowers 4-merous, on pedicel 0.2-0.5(-1.0) mm long. Sepals 4, deltoid, 0.2 mm long, 0.2 mm wide. Petals 0. Stamens 0. Styles 4, alternating with sepals, 0.4 mm long, stigmas fimbriate, white, sometimes grading to pale pink. Ovary obpyriform, 0.6 × 0.5 mm, channelled opposite sepals, 4-locular. Fruit sessile or shortly pedunculate, red-purple, ovoid to obpyriform, 1.0-1.5 × 1.1-1.2 mm, deeply channelled opposite sepals, smooth to weakly striated, not verrucose; sepals usually persistent, membranous, 0.2 × 0.2 mm; styles persistent, becoming reflexed. Fruit splitting at maturity into 4 single-seeded mericarps. Mericarps ± globular with attenuate neck formed from persistent style.
Easily grown from fresh seed and rooted pieces. must be kept moist. An interesting plant for a small pond or fish tank.
myriophyllum: Many leaves
pedunculatum: Flowers stalked
novae-zelandiae: Of New Zealand
Where To Buy
Not Commercially Available
Fact Sheet Prepared by P.J. de Lange (1 November 2009). Description based on Orchard (1979).
References and further reading
Orchard, A.E. 1979: Myriophyllum (Haloragaceae) in Australasia. 1. New Zealand: a revision of the genus and a synopsis of the family. Brunonia 2: 247-287.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Myriophyllum pedunculatum subsp. novae-zelandiae Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/myriophyllum-pedunculatum-subsp-novae-zelandiae/ (Date website was queried)