Ileostylus micranthus
Common names
Green mistletoe, pirita
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Trees & Shrubs - Dicotyledons
Simplified description
Bushy yellowish-green shrub growing on other trees with clusters of tiny green flowers and orange fruit. Leaves fleshy, variable in shape, 30-80mm long, in pairs on stalks that arise from a flattened section of the squareish stem. Roots creeping along host plant’s stem.
Flower colours
Green
Detailed description
Woody, epiphytic much branched, bushy hemiparasite. producing multiple haustoria (these attaching at intervals long host branch) and epicortical, often spiraled roots. Leaves opposite, coriaceous. Petioles`5-50 mm long, flattened and slightly winged. lamina 30-60(-80) × 15-40(-68) mm, dark green to yellow-green, broadly elliptic, slightly ovate, ovate, obovate to rhomboid, base attenuate, apex obtuse to rounded. Inflorescences axillary, solitary of paired, in cymose panicles, these 10-15(-20) mm long with 8-9-12(-15) flowers arranged in threes. Flowers male, female or hermaphroditic (the dioecious condition most commonly seen when Ileostylus is parasitic on species of totara (Podocarpus spp.). Calyx cylindrical, presenting as an truncate rather obscure narrow rim 0.2 mm high. Petals 4, free, c.3-4 mm × 0.8-1.6 mm, greenish to yellow-green. Anthers 4, basifixed. Style contorted, usually initially coiled in middle, up to 3.0-4.5 mm long when uncoiled. Ovary 1-locular. Fruit a 1-seeded, 5-8 mm, yellow or orange, ellipsoid or globular (rarely ellipsoid-globular) berry. Seed 5.0-5.5 mm long, elliptic, rounded at both ends, terete.
Similar taxa
Tupeia antarctica is often confused with Ileostylus. Ileostylus differs from Tupeia by its external rather than internal haustoria; having multiple haustoria and epicortical roots; by the styles of the flowers which are characteristically ‘bent’ rather than straight; by the yellow or orange rather than white or white spotted purple fruit; and by the young stems that are squarish rather than round (terete) in cross-section.
Distribution
Indigenous. North, South and Stewart Islands, also on Norfolk Island.
Habitat
Mainly a coastal and lowland species which rarely extends into upper montane forest. Prefers shrubland and secondary regrowth. This species shows some regional host specificity but nevertheless has been recorded from a wide range (nearly 300) of indigenous and exotic hosts. One of the few indigenous mistletoe’s to regularly grow in urban situations.
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 | Not Threatened | Qualifiers: TO
Detailed taxonomy
Genus
Family
Synonyms
Loranthus micranthus Hook.f.
Endemic taxon
Yes
Endemic genus
Yes
Endemic family
No
Ecology
Flowering
September - December
Fruiting
December - July
Life cycle and dispersal
Fleshy berries are dispersed by frugivory (Thorsen et al., 2009).
Propagation technique
Difficult. For best results use fresh fruit. Fruit should be squeezed gently so that seed is exposed. The exposed seed should be placed on a suitable host branchlet (ideally in dry weather so that the fruit does not wash off), and allowed to dry. Sometimes the fruit may need to be covered with netting to exclude birds. Then its up to the Gods! Seed almost always germinates (it will even germinate on glass) but unless an attachment is formed (and this may take months) the young plant soon dies. Some people find growing Ileostylus straight forward, others tricky. The process is often rather hit and miss and best results seem to be achieved when seed is placed on the same host plant (ideally the same genotype of the host) as that parasitized by the mother plant.
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). If you have suggestions for the Wetland Indicator Status Rating, please contact: [Enable JavaScript to view protected content]
UPL: Obligate Upland
Rarely is a hydrophyte, almost always in uplands (non-wetlands).
Other information
Etymology
ileostylus: Style folded like a small intestine
micranthus: Small flower
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.
ILEMIC
Chromosome number
2n = 22
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 | Not Threatened | Qualifiers: TO
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Regional conservation statuses
Auckland: 2025 | Regionally Threatened – Regionally Endangered | Qualifiers: CD, DPS, DPT, PF, RR, TO
The regional threat classification system leverages off the national assessments in the NZTCS, providing information relevant for the regional context. Auckland conservation status information is sourced from the “Conservation status of vascular plant species in Tāmaki Makaurau / Auckland” Simpkins E et al. (2025) report.
Otago: 2025 | Regionally Not Threatened
The regional threat classification system leverages off the national assessments in the NZTCS, providing information relevant for the regional context. Otago conservation status information is sourced from the “Conservation Status of Indigenous Vascular Plants in Otago, 2025” Jarvie S et al. (2025) report.
Referencing and citations
References and further reading
Duguid, F. 1967. Hosts of Loranthus micranthus. Wellington Botanical Society Bulletin, 34: 23-24
Menzies, B. 1945. Loranthus micranthus. Auckland Botanical Society Journal, 2: 8-9
Stanley, R. 1998. Mistletoe hunt in Hunua. Auckland Botanical Society Journal, 53: 74-75
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
Attribution
Factsheet and description prepared for the NZPCN by P.J. de Lange (7 May 2011).
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Ileostylus micranthus Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/ileostylus-micranthus/ (Date website was queried)