Species

Potamogeton ochreatus

Etymology

Potamogeton: river dweller

Common Name(s)

blunt pondweed

Current Conservation Status

2012 - Not Threatened

Conservation status of New Zealand indigenous vascular plants, 2012
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2012 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2009 and replaces all previous NZTCS lists for vascular plants. Authors: Peter J. de Lange, Jeremy R. Rolfe, Paul D. Champion, Shannel P. Courtney, Peter B. Heenan, John W. Barkla, Ewen K. Cameron, David A. Norton and Rodney A. Hitchmough. File size: 792KB

Previous Conservation Status

2009 - Not Threatened
2004 - Not Threatened

Authority

Potamogeton ochreatus Raoul

Family

Potamogetonaceae

Flora Category

Vascular - Native

NVS Species Code

POTOCH

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.

Structural Class

Monocotyledonous Herbs

Synonyms

None

Distribution

Indigenous. New Zealand: North, South, Auckland Islands. Also Australia and South-East Asia

Habitat

Coastal to lowland in slow moving waters such as rivers, streams, also found in lakes and ponds, especially near lake outlets

Features

Aquatic, submerged, rhizomatous perennial herb. Rhizome short, invested with closely set fibrous stipules and roots. Branches erect, at first simple bearing long leaves, then branching up to eight times at leaf axils, branchlets short, produced in spring and elongating in autumn, sometimes rooting from nodes. Stipules to 20 mm long, free, open, obtuse, disintegrating into fibres with age at older nodes (fibres derived from close-set nerves). Leaves all submersed, sessile; lamina 15–100 × 2–5 mm, entire, linear-oblong, obtuse to slightly emarginate, only slightly narrowed to base, membranous, longitudinal nerves 8, fine and close, one in each half usually stronger than the rest. Inflorescence a densely flowered spike up to 15 mm long. Peduncles 20-40 mm long, simple, slender, arising from axils of upper leaves within the short branchlets. Achenes c.3.0 × 2.5 mm, flattened on sides, keel ± 3-ridged, beak rather well-developed, curved.

Similar Taxa

Distinguished from all other Potamogeton in New Zealand, except P. crispus by the grass-like, parallel-sided submerged and emergent leaves, bearing numerous, close set, fine longitudinal nerves (these occasionally obscure); and by the fibrous stipules. The naturalised Potamogeton crispus differs by having only submersed, oblong leaves with crimped margins and bearing 3-5 longitudinal nerves.

Flowering

November - April

Fruiting

December - May

Propagation Technique

Can be grown in ponds and slow-flowing streams. Also an excellent plant for an indoor aquarium. Sometimes can become invasive.

Threats

Not Threatened

Endemic Taxon

No

Endemic Genus

No

Endemic Family

No






Attribution

Fact sheet prepared for NZPCN by P.J. de Lange (16 February 2012). Description adapted from Moore & Edgar (1970)

References and further reading

Moore, L.B.; Edgar, E. 1970: Flora of New Zealand. Vol. II. Government Printer, Wellington.

This page last updated on 11 Aug 2014