Isolepis inundata
Biostatus
Native
Category
Vascular
Structural class
Sedges
Detailed description
Initially tufted, with culms soon arching and spreading. Culms 60–500 × 0.4–1.8 mm, tufted, numerous, erect, often rather rigid (especially in lower third), terete, bright green. Leaves 1, or rarely 2–3 at the base of the culm, < 1 mm. wide; frequently reduced to a single, mucronate, red basal bract, mucro usually short. Inflorescence an apparently lateral, solitary head of (1)–3–6–(10) crowded spikelets, often proliferous with 1–3 slender branchlets each terminated by a smaller head of spikelets, subtending bract usually slightly > spikelets. Spikelets 2.0–5.0 × 1.5–3.0 mm, ovate or oblong-ovate, often dark red-purple. Glumes 1.5–2.0 mm. long, oblong-obovate, obtuse or ± acute, with a large dark red to black patch on either side of the pale green keel, with numerous distinct, light brown nerves, margins entire, white and membranous, flattened at the tip beside the keel. Hypogynous bristles 0. Stamen 1, very rarely 2. Style-branches 3, rarely 2–3. Nut c. 1.0 × 0.5 mm, slightly > ½ length of glume, conspicuously trigonous (very occasionally biconvex), distinctly mucronate, pale straw-coloured, almost white, occasionally grey-brown, surface distinctly reticulate.
Similar taxa
Close to Isolepis distigmatosa (C.B.Clarke) Edgar and I. prolifera (Rottb.) R.Br. in often having no true leaves but only sheathing bracts. It is distinguished from these species by its usually pale green basally blotched dark red or purple glumes, mostly 3 rather than 2 style-branches, and trigonous (rarely biconvex) nuts. It is usually a much finer plant than either of these species.
Distribution
Indigenous. New Zealand: North Island, South Island and Chatham Islands. Also Australia, Malaysia, South America and Norfolk Island.
Habitat
Coastal to montane in fresh water wetlands (eutrophic to oligotrophic). Often forming a floating sud around lake, pond and stream margins. Sometimes colonising old water troughs and damp pasture.
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: SO
Detailed taxonomy
Family
Synonyms
Scirpus inundatus (R.Br.) Spreng.; Scirpus inundatus var. major Cheeseman; Isolepis propinuqua R.Br.; Scirpus cartilagineus var. propinqua (Nees) Benth.; Isolepis conspersa Nees in Endl.; Scirpus conspersus (Nees) Boeck.; Isolepis gunnii Steud.; Isolepis urvillei Steud.; Scirpus urvillei (Steud.) Boeck.; Isolepis multinervosa Boeck.
Endemic taxon
No
Endemic genus
No
Endemic family
No
Ecology
Flowering
September–January
Fruiting
October–June
Life cycle and dispersal
Nuts are dispersed by water and possibly granivory and attachment (Thorsen et al., 2009).
Propagation technique
Easily grown from fresh seed and by division of whole plants. Once established rather tolerant of a range of conditions but flourishes best in full sun in a permanently damp soil. An attractive pot plant but can become invasive in some situations.
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]
OBL: Obligate Wetland
Almost always is a hydrophyte, rarely in uplands (non-wetlands).
Other information
Where To Buy
Not commercially available
Etymology
isolepis: From the Greek isos (equal) and lepis (scale)
inundata: Growing in places that are periodically flooded
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.
ISOINU
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: SO
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Regional conservation statuses
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 “Regional conservation status of indigenous vascular plants in Otago” Jarvie S et al. (2024) report.
Otago: 2024 | Regionally Data Deficient
Referencing and citations
References and further reading
Johnson AT, Smith HA. 1986. Plant Names Simplified: Their pronunciation, derivation and meaning. Landsman Bookshop Ltd, Buckenhill, UK.
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 Moore and Edgar (1970)
Some of this factsheet information is derived from Flora of New Zealand Online and is used under a Creative Commons Attribution 3.0 New Zealand licence.