Korthalsella salicornioides
Common names
dwarf mistletoe
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Trees & Shrubs - Dicotyledons
Simplified description
Dense mass of green to reddish-yellow beaded succulent stems to 10cm long growing on twigs of another plant (mainly mānuka and kānuka). Leaves (stems) 3–10mm long by 1–3mm wide, round. Flowers tiny, fruit small, yellowish.
Detailed description
Hemiparasitic, succulent, much branched, green, yellow-green, red-green to orange-green plant parasitising exposed branches and branchlets of host. Haustoria internal, dark green, encircling stele of host. Plants 30–100 × 10–450 mm, erupting from host bark, individual aerial structures lasting from 1–4 years before dehiscing and resprouting. Branches arising at narrow angles. Internodes terete, succulent to subsucculent, 3–10 × 1–3 mm, narrowed to a finely constricted node. Collar truncate, up to 0.5 mm long, sheathing at nodes. Flowers scarcely differentiated from barren stems, 3–10 × 1 mm. Fruit 1.5 mm long, ovoid to globular, dispersed by birds or ejected under hydraulic pressure.
Similar taxa
None. The two other species of Korthasella Tiegh. endemic to New Zealand have flattened internodes are fewer branches arising at wider angles.
Distribution
Endemic. New Zealand: North Island (from Te Paki south), South Island, Stewart Island/Rakiura. Easily overlooked.
Habitat
Coastal to upper montane and subalpine (0–1300 m a.s.l.). A parasite found in forest and shrublands. Most commonly found parasitic on Leptospermum scoparium J.R.Forst. et G.Forst. (kahikatoa/mānuka) and species of Kunzea (rawiri/titiri/kānuka).
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.
Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – these interim threat classification statuses has not been assessed by the NZTCS panel.
- 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 | At Risk – Declining | Qualifiers: Sp, DPT
Threats
An apparently naturally uncommon and biologically sparse species which can on occasion be locally abundant, but is more usually known from large parts of its likely range by only spot or scattered occurrences. In some parts of its range it is under threat due to the felling of its main host species (Leptospermum and Kunzea) for firewood and also to clear land for farming or pine plantations.
When myrtle rust (Austropuccinia psidii) was detected in New Zealand (May 2017) the conservation status of Korthalsella salicornioides was upgraded as a precautionary measure to ‘Threatened – Nationally Critical’ because, on best advice, it was believed that no indigenous Myrtaceae had resistance to the myrtle rust disease (de Lange et al. 2018). Korthalsella salicornioides is almost exclusively parasitic on species of Leptospermum and Kunzea, both genera in the Myrtaceae family. Currently there have been no reports of infected wild trees of Kunzea but inoculation trials of the New Zealand species has demonstrated they are susceptible and that, over time, infected specimens will die. Only time will tell if wild populations of Kunzea and Leptospermum will be threatened by this rust fungus.
Myrtle rust (Austropuccinia psidii) is an invasive fungus that threatens native myrtle species. Learn more myrtlerust.org.nz.
Detailed taxonomy
Family
Viscaceae
Synonyms
Viscum salicornioides A.Cunn.
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
October–March
Fruiting
October–May
Life cycle and dispersal
Fleshy berries are dispersed by ballistic projection, attachment and possibly frugivory (Thorsen et al., 2009).
Propagation technique
Difficult—should not be removed from the wild.
Other information
Host notes
The most host-specific of the three New Zealand species of the genus, the favoured host is Leptospermum scoparium followed by Kunzea species. However Sophora chathamica Cockayne, Myrsine australis (A.Rich.) Allan, Dracophyllum acerosum Bergg., Melicope simplex A.Cunn. and Gaultheria antipoda G.Forst. are sometimes also parasitised.
Plant of the Month
This plant has been featured as a Plant of the Month – see Trilepidea: NZPCN newsletter for August 2020 for the full story.
Etymology
korthalsella: After Korthals, botanist
salicornioides: Like Salicornia (glasswort)
NVS code
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.
KORSAL
Chromosome number
2n = 28
Previous conservation statuses
2017 | Threatened – Nationally Critical | Qualifiers: DP, Sp
2012 | At Risk – Naturally Uncommon | Qualifiers: Sp
2009 | At Risk – Naturally Uncommon | Qualifiers: EF
2004 | Sparse
Referencing and citations
References and further reading
Cameron EK. 2001. Korthalsella salicornioides discovered close to Auckland city. Auckland Botanical Society Journal 56: 53–54.
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.
Nickrent DL, Malécot V, Vidal-Russell R, Der JP. 2010. A revised classification of Santalales. Taxon 59: 538–558. https://doi.org/10.1002/tax.592019.
Thorsen MJ, Dickinson KJM, Seddon PJ. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 11: 285–309. https://doi.org/10.1016/j.ppees.2009.06.001.
Attribution
Fact sheet prepared by P.J. de Lange for NZPCN (1 June 2013).
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Korthalsella salicornioides Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/korthalsella-salicornioides/ (Date website was queried)