Apodasmia similis
Common names
jointed wire rush, oioi
Biostatus
Native
Category
Vascular
Structural class
Rushes & Allied Plants
Flower colours
Brown, Red/Pink
Detailed description
Dioecious, rush-like perennial herb. Rhizomes 3–7 mm diameter, covered in closely sheathing, imbricating, dark brown scales, 10–20 mm long, each enclosing a tuft of coarse brown hairs. Culms numerous, 0.5–2.6 × 1.5–2.5–(3.0) mm, densely packed, erect, sometimes with upper third decurved to more or less pendulous, simple, terete, glaucous, grey-green, yellow-green or red-green. Leaves reduced to bract-like sheaths, these dark brown or maroon-black, regularly spaced at 70–90 mm intervals at the base of the culm, 10–60 mm apart higher up; margins entire. Male inflorescences paniculate or fascicled, bearing numerous stalked spikelets; upper floral bracts ovate-lanceolate, mucronate, red-brown to maroon, margins membranous; tepals 4–6 more or less completely hyaline, the outer longer, brownish, the inner shorter, paler; stamens 3; ovary rudimentary. Female inflorescences fascicled, spikelets more or less sessile; upper floral bracts ovate, mucronate, > tepals; tepals 6, the outer keeled, lanceolate, acuminate, inner flat, smaller, more or less hyaline, more obtuse, mucronate; styles 3, united to midway, bright red to orange-red; staminodes 0. Fruit c. 1 × 0.5 mm, triquetrous, indehiscent. Seed c. 1 × 0.4 mm, oblong-elliptical, golden-brown, surface reticulate, both ends apiculate, one end dark brown, the other, almost white.
Similar taxa
Easily distinguished from Sporadanthus F.Muell and Empodisma L.A.S.Johnson et D.F.Cutler by the unbranched, mostly grey-green, or reddish stems bearing regularly spaced bract-like, sheathing dark brown or maroon-black leaves, and terminal, many-flowered, paniculate to fascicled male and female spikelets.
Distribution
Endemic. Three Kings, North, South, Stewart and Chatham Islands.
Habitat
Mostly coastal in estuaries, saltmarshes, dunes and sandy flats and hollows. Occasionally inland in gumland scrub, along lake margins, fringing peat bogs or surrounding hot springs.
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 | Not Threatened
Detailed taxonomy
Family
Restionaceae
Synonyms
Leptocarpus similis Edgar
Taxonomic notes
Needs critical comparison with Apodasmia chilensis (Gay) B.G.Briggs et L.A.S.Johnson, particularly the Chatham Island plants which seem a close match for that South American species.
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
October–December
Fruiting
December–March
Life cycle and dispersal
Fruit are possibly disperesed by water and wind (Thorsen et al., 2009).
Propagation technique
Easily grown from fresh seed and rooted pieces. Does well in a range of soils and moisture regimes. Requires full sun to flourish. Now a very popular tub and traffic island plant in some cities—most material seen is from the 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). If you have suggestions for the Wetland Indicator Status Rating, please contact: [Enable JavaScript to view protected content]
FACW: Facultative Wetland
Usually is a hydrophyte but occasionally found in uplands (non-wetlands).
Other information
Cultivation
Occasionally available from mainstream plant and specialist native plant nurseries. Most stock seen is of the large, glaucous Chatham Island form.
Etymology
apodasmia: From the Greek apodasmios meaning ‘separated’, referring to the widely disjunct distribution of the species (there are two species in Australia, one in New Zealand and one in Chile) (Briggs & Johnson, 1998)
similis: Similar to another species
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.
APOSIM
Chromosome number
2n = 48
Previous conservation statuses
2017 | Not Threatened
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Referencing and citations
References and further reading
Briggs BG, Johnson LAS. 1998. New genera and species of Australian Restionaceae (Poales). Telopea 7(4): 345–373.
Moore LB, Edgar E. 1970. Flora of New Zealand, Volume II. Indigenous Tracheophyta: Monocotyledones except Gramineae. Government Printer, Wellington, NZ. 354 p.
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.
Attribution
Description adapted from Edgar and Moore (1970).
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Apodasmia similis Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/apodasmia-similis/ (Date website was queried)