Dysphania pusilla
Common names
pygmy goosefoot
Biostatus
Native
Category
Vascular
Structural class
Herbs - Dicotyledons other than Composites
Flower colours
Green, Yellow
Detailed description
Annual, cushion-forming, yellow-green, prostrate herb with all parts finely glandular hairy. Leaves suborbicular (nearly circular in profile), broadly ovate to ovate-oblong, margins entire, or sinuate (wavy) sometimes deeply lobed. Flowers minute, greenish-yellow, in dense axillary clusters (glomerules), perianth (united floral envelopes) divided into (3)–4–(5) segments. Stamen 1–(2). Seed 0.5–0.8 mm diameter, dark red brown, aligned vertical in perianth.
Similar taxa
Dysphania pusilla is very similar to some of the small forms of the introduced Australian D. pumilio. The key differences are that D. pumilio usually has (4)–5 perianth segments, slightly larger seeds, and more deeply divided leaves.
Distribution
Endemic. New Zealand: North Island (Formerly recorded at Lake Taupo and Wairarapa). South Island (rediscovered 2015 in eastern Molesworth Station and the Ruataniwha wetlands (Clayton-Greene et al. 2015).
Habitat
Open or sparsely-vegetated ground such as clay and salt plans, dried out river and lake beds. Also collected from cultivated land and railway yards.
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 | Threatened – Nationally Endangered | Qualifiers: Sp, DPR, DPT, EF
Threats
Formerly assessed as ‘Taxonomically Indeterminate – Extinct’ (de Lange et al. 2013) but, following its rediscovery some 65 years after it was last seen (Clayton-Greene et al. 2016), the species is now listed as ‘Threatened – Nationally Endangered’ (de Lange et al. 2018). For more information see below.
Detailed taxonomy
Genus
Family
Synonyms
Chenopodium pusillum Hook.f.; Dysphania pusilla (Hook.f.) Paul G.Wilson et K.A.Sheph. nom., superf.
Taxonomic notes
On the basis of molecular phylogenetic evidence the genus Dysphania R.Br. has been reinstated (see Mosyakin & Clemants 2002; Shepherd & Wilson 2008, 2009). the genus is distinguished from Chenopodium s.s. by their minute flowers which occur in compact, cymose clusters and by the presence of subsessile glands or simple and acuminate, multicellular, glandular hairs as well as DNA evidence (see summary by Shepherd & Wilson 2008).
Dysphania pusilla presents somewhat of an enigma in the New Zealand Flora. Herbarium records suggest it was never common in the North Island, where it was collected as a ‘weed’ in Māori gardens. Historical South Island records tend to correlate to old sheep runs with one 1950s record from a railway yard in Christchurch. The species was not then seen again until the summer of 2014–2015 when it was discovered in a remote portion of the upper Clarence River, and in parts of the McKenzie Basin (Clayton-Greene 2015). No one is sure why it vanished for some 65 years, only to reappear in several locations, sometimes as 1000s of plants. The habitats occupied are not singular but rather widespread, mostly weedy, often heavily grazed, though one is within a fenced wetland system set up for threatened wading birds (where water levels are artifically controlled). Although many plants were seen in 2015/2016, the area of occupancy is small, and the species is potentially threatened from competition by weeds if grazing pressure is reduced. For this reason Dysphania pusilla, once regarded as ‘Extinct’, has been assessed as ‘Nationally Endangered’ (de Lange et al. 2018).
One pressing issue remains. Is Dysphania pusilla truly indigenous / endemic? Preliminary DNA data based on one marker (nrDNA ITS) places this species with D. pumilio. Further study of the relationship of Dysphania pusilla with D. pumilio—a very variable species in Australia—is needed. It may well be that Dysphania pusilla is also in Australia, and that it may even be an early introduction to New Zealand.
Endemic taxon
Indeterminate
Endemic genus
No
Endemic family
No
Ecology
Flowering
November–March
Fruiting
December–May
Life cycle and dispersal
Annual.
Propagation technique
Easily grown from seed. A short-lived annual that self-establishes in sites where it has been grown.
Other information
Etymology
pusilla: Small
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 | Threatened – Nationally Endangered
2009 | Extinct
2004 | Data Deficient
Referencing and citations
References and further reading
Clayton-Greene, J.; Courtney, S.; Rebergen, A.; Head, N. 2015: The rediscovery of the presumed extinct Dysphania pusilla. Trilepidea 139: 1-3.
de Lange PJ, Rolfe JR, Barkla JW, Courtney SP, Champion PD, Perrie LR, Beadel SM, Ford KA, Breitwieser I, Schönberger I, Hindmarsh-Walls R, Heenan PB, Ladley K. 2018. Conservation status of New Zealand indigenous vascular plants, 2017. New Zealand Threat Classification Series 22. Department of Conservation, Wellington, NZ. 82 p. https://www.doc.govt.nz/globalassets/documents/science-and-technical/nztcs22entire.pdf.
de Lange PJ, Rolfe JR, Champion PD, Courtney SP, Heenan PB, Barkla JW, Cameron EK, Norton DA, Hitchmough RA. 2013. Conservation status of New Zealand indigenous vascular plants, 2012. New Zealand Threat Classification Series 3. Department of Conservation, Wellington, NZ. 70 p. https://www.doc.govt.nz/globalassets/documents/science-and-technical/nztcs3entire.pdf.
Mosyakin SL, Clemants SE. 2002: New nomenclatural combinations in Dysphania R.Br. (Chenopodiaceae): taxa occurring in North America. Ukrainia Botanical Journal 59: 380–385. https://www.researchgate.net/publication/272417640_New_nomenclatural_combinations_in_Dysphania_RBr_Chenopodiaceae_Taxa_occurring_in_North_America.
Shepherd KA, Wilson PG. 2008. New combinations in the genus Dysphania (Chenopodiaceae). Nuytsia 18: 267–272. https://doi.org/10.58828/nuy00534.
Shepherd KA, Wilson PG. 2009. Clarification of recent combinations in the genus Dysphania (Chenopodiaceae) Nuytsia 19: 198–199. https://doi.org/10.58828/nuy00567.
Attribution
Fact Sheet prepared and updated for NZPCN by P.J. de Lange (30 August 2018)
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Dysphania pusilla Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/dysphania-pusilla/ (Date website was queried)