Apium prostratum subsp. prostratum var. filiforme
Common names
New Zealand celery
Biostatus
Native
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
Category
Vascular
Structural class
Herbs - Dicotyledons other than Composites
Flower colours
Cream, Yellow
Detailed description
Perennial, glabrous, prostrate herb. Stems prostrate, sprawling, often ascending though surrounding vegetation, not rooting at nodes; 0.3-1.2 m long, up to 6 mm diam. Leaves dark green to yellow green, basal ones on long, slender petioles up to 500 mm (usually much less); pinnately 3-foliolate to 1-2-pinnate; segments ovate, obovate to cuneate, deeply incised and toothed; Leaves opposite compound umbels similar though with leaflets divided, elliptic, ovate, obovate or more or less cuneate, primary segments elliptic, ovate, obovate, or more or less cuneate in outline, with overall length 0.5-3x the greatest breadth, ultimate segments to tertiary order 8-74 per leaf. Inflorescences in compound umbels, sessile or pedunculate; peduncle usually present. 2-20 mm x 1-3 mm, usually ebracteate, sometimes one present present, this usually shedding early in umbel maturation. Rays 10-20, 0.4-8 mm long. Petals off-white to cream, with yellow-brown mid vein, ovate 0.75-1.5 x 0.5-1.0 mm, constricted at base, apex acute. Stamens about length of petals, filaments pale yellow to cream; anthers whitre or pale yellow, 0.3-0.4 x 0.3-0.4 mm. Ovary glabrous, stylopodium disciform; style 0.25-0.40 mm. Mericarps (1.5-)2.0-2.7 mm long, ovate to ovate-oblong, apex narrowed to persistent withered calyx teeth and style remnant, base broad and rounded to weakly cordate; ribs prominent, broad, rounded and spongy. Surface dull yellow to pale brown.
Similar taxa
Garden celery (Apium graveolens) is occasionally found wild and can look very similar. It is an erect, biennial herb with filiform ribs on the mericarps (fruits). Water celery (Apium nodiflorum (L.) Lagasca is a species of freshwater systems where it grows along drains, river, stream, lake and pond margins. Its umbels are always bracteolate, and the stems root freely at the nodes. The Chatham Island endemic A. prostratum subsp. denticulatum P.S.Short, differs by its allopatric distirbution, and by the leaves opposite the umbels up to 60 mm long; primary leaflets 3-5, leaflets or segments markedly denticulate with 6-36 secondary segments per leaflet only.
Distribution
Indigenous. In New Zealand known from the Kermadec, Three Kings, North, South, Stewart and Antipodes Islands. Also in eastern Australia as far north as Brisbane and along the whole coastline of southern Australia and Tasmania
Habitat
Coastal and lowland. Very rarely montane. Common on rock ledges, boulder falls, cliff faces, within petrel scrub on damp seepages, in peaty turf, saltmarshes, within estuaries on mud banks, around brackish ponds, and lagoons. Also found in freshwater systems such as around lake and tarn sides, along streams and rivers and in wet hollows occasionally well inland, and sometimes at considerable elevations.
Detailed taxonomy
Genus
Family
Synonyms
Petroselinum prostratum (Labill ex Vent.) DC., Helosciadium prostratum (Labill. ex Vent.) Bunge in Lehm., Petroselinum filiforme A.Rich., Apium filiforme (A.Rich.) Hook., Apium australe auct. non Pet.-Thou.
Taxonomic notes
New Zealand plants of Apium prostratum are extremely variable and at least one entity currently included within var. filiforme is apaprently unnamed. These plants are usually found on muddy ground within saltmarshes, in brackish ponds, and sometimes inland around lakes, stream and river sides. The variant has very slender leaves, often purplish petioles and distinct white piliferous to markedly apiculate leaf apices. It has long been known under the tag names White Denticles and Slender. It warrants more study.
Endemic taxon
No
Endemic genus
No
Endemic family
No
Ecology
Flowering
August - March
Fruiting
September - July
Life cycle and dispersal
Corky mericarps are dispersed by water (Thorsen et al., 2009).
Propagation technique
Easily grown from fresh seed and whole plants. Being edible and pleasant tasting it could be more widely used as a substitute for celery (Apium graveolens L.).
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]
FAC: Facultative
Commonly occurs as either a hydrophyte or non-hydrophyte (non-wetlands).
Other information
Etymology
apium: The ancient Latin name for celery or parsley. Believed to be derived from the Celtic word apon ‘ditch’ and refers to the watery habitat of many species
prostratum: Prostrate
filiforme: From the Latin filum ‘thread’ and forma ‘shape’, meaning thread-shaped
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.
APIPVF
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: SO
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Regional conservation statuses
Auckland: 2025 | Regionally Not Threatened | Qualifiers: DPS
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
Johnson, A. T., Smith, H. A. (1972). Plant Names Simplified: Their pronunciation, derivation and meaning. Landsman Bookshop Ltd: Buckenhill, UK.
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 2009 Vol. 11 No. 4 pp. 285-309
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): Apium prostratum subsp. prostratum var. filiforme Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/apium-prostratum-subsp-prostratum-var-filiforme/ (Date website was queried)