Wilsonia backhousei
Common names
Narrow-leaved wilsonia
Biostatus
Native
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 | Non-resident Native – Coloniser | Qualifiers: SO
Category
Vascular
Structural class
Herbs - Dicotyledons other than Composites
Flower colours
Violet/Purple
Detailed description
Small procumbent subshrub forming dense patches up to 1 x 1 m. branches procumbent up to 150 mm tall, more or less glabrous. Leaves more or less succulent, sessile, 5-20 x 10-3 mm, glaucous to dark green, linear-lanceolate to linear-obovate, apex acute, base attenuate, glabrous. Flowers solitary; pedicels 0-1.5 mm long, calyx 5-7 mm long, tubular, teeth 5, triangular, 1/4 to 1/3 the length of tube, outer surface glabrous, inner pilose hairy; corolla 10 mm long, tubular white; 5-lobed, lobes 2-4 mm long, linear-ovate to linear-elliptic, acute; stamens 5, exserted, filaments attached 1-1.5 mm below throat; ovary 1-2-locular, style exserted, stigmas ovoid. Capsule c.3 mm long, obovoid, shorter than calyx, indehiscent (capsules rarely seen in New Zealand material). Seeds 1-2.
Similar taxa
None. Though the grey-green, succulent leaves mean that sterile plants could be confused with Suaeda novae-zelandiae Allan which grows in similar habitats. From Suaeda, Wilsonia differs by its more upright growth habit and solitary, white, tubular non-bracteolate rather than the compact green or red-green, bracteolate flowers of Suaeda.
Distribution
Indigenous. In New Zealand known only from the Waimea Estuary, Nelson where it was first discovered in 1993. Common in Australia where it is known from Western Australia, South Australia, Victoria, New South Wales and Tasmania.
Habitat
A species of usually silty to muddy ground within estuaries, usually found growing just above the mean high tide mark in places which would be subjected to frequent salt-water immersion during storms or Spring/King tides.
Threats
Not Threatened. Apparently a recent arrival ( at least there are no records of it prior to 1993) which has successfully colonised the Waimea Estuary. It shoudl probably no longer be regarded as a vagrant, despite the fact it rarely sets seed. For it spreads readily by asexual means.
Detailed taxonomy
Genus
Family
Synonyms
None
Taxonomic notes
Actively and aggressively spreading, this species may require management and control. It could be introduced. As far as is known all spread is vegetative, fruit being rarely (if ever) formed in New Zealand populations
Endemic taxon
No
Endemic genus
No
Endemic family
No
Ecology
Flowering
October - February
Fruiting
December - April (rarely produced in New Zealand)
Propagation technique
Easily grown from stem cuttings. However, requires a water logged soil in full sun to flourish. In good conditions inclined to become invasive.
Other information
Etymology
wilsonia: Named after John Wilson, 18th century amateur botanist and author of A Synopsis of British Plants, published in 1744
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 | Non-resident Native – Coloniser | Qualifiers: SO
2012 | Non-resident Native – Coloniser | Qualifiers: SO
2009 | Non-resident Native – Coloniser | Qualifiers: SO
2004 | Non-resident Native – Vagrant
Referencing and citations
Attribution
Fact Sheet prepared for the NZPCN by P.J. de Lange 14 April 2006. Description by P.J. de Lange.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Wilsonia backhousei Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/wilsonia-backhousei/ (Date website was queried)