Triglochin palustris
Common names
marsh arrow grass
Biostatus
Native
Category
Vascular
Structural class
Herbs - Monocots
Flower colours
Green, Red/Pink
Detailed description
Summer green, erect, slender, bulbous herb forming small colonies. Leaves dark green to reddish-green, 50-500(-800) x 0.5-1 mm diam., fleshy, semicircular or slightly channelled in cross-section. Ligules undivided, subacute. Inflorescence arising on a stout peduncule 25-260(-400) mm long; racemose, with raceme more or less equal to peduncle length. Flowers pedicellate, pedicels up to 6 mm long, closely appressed to peduncle axis. Flowers c. 3 mm long, dark green to wine-red. Fruit 80-100 x 1 mm, narrow-linear, with the 3 fertile follicles unkeeled, dorsifixed, partially separating from the base, resulting in an arrow shaped structure.
Similar taxa
A distinctive species, immediately recognised by the arrow-head fruits borne on a long slender raceme are imemdiately diagnostic. Occasionally Triglochin striata may grow inland in similar habitats. It is a much smaller plant, lacking a bulbous base, with rounded leaf ligules, and fruits that are subglobose rather than arrow-shaped.
Distribution
Indigenous. In New Zealand known only from the eastern side of the South Island, where it has been reported from South Canterbury, Northern and Central Otago.
Common in the Northern Hemisphere and South America.
Habitat
Montane wetlands. Found growing along the sides of slow flowing streams, on tarn and lake margins and in sphagnum bogs.
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 | Threatened – Nationally Endangered | Qualifiers: Sp, DPS, DPT, RR, SO
Threats
Herbarium records indicate that this species has always been localised. However, it is also easily overlooked. Nevertheless some Canterbury sites have vanished and in some of the Otago sites the species is very vulnerable to weed invasion of its wetland habit. Very few populations occur on protected land, and many are accessible to livestock which greedily eat plants.
Detailed taxonomy
Family
Juncaginaceae
Synonyms
Triglochin palustre L.
Endemic taxon
No
Endemic genus
No
Endemic family
No
Ecology
Flowering
December to February
Fruiting
December to March
Propagation technique
Can be grown in damp soil or partially submerged pots from divisions or whole plants. Fresh seed should germinate easily.
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
Etymology
triglochin: Three-pointed
palustris: From the Latin palus ‘swamp’, meaning growing in swamps
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.
TRIPAL
Chromosome number
2n = 24
Previous conservation statuses
2017 | Threatened – Nationally Critical | Qualifiers: DP, RR, SO, Sp
2012 | Threatened – Nationally Critical | Qualifiers: RR, SO, Sp
2009 | Threatened – Nationally Critical | Qualifiers: SO, DP
2004 | Threatened – Nationally Endangered
Referencing and citations
References and further reading
Moore, L.B.; Edgar, E. 1970: Flora of New Zealand. Vol. I. Government Printer, Wellington.
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.