Potamogeton cheesemanii
Common name
red pondweed
Synonyms
None
Family
Potamogetonaceae
Flora category
Vascular – Native
Endemic taxon
No
Endemic genus
No
Endemic family
No
Structural class
Herbs - Monocots
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.
POTCHE
Chromosome number
2n = 28
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2017 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants. Authors: By Peter J. de Lange, Jeremy R. Rolfe, John W. Barkla, Shannel P. Courtney, Paul D. Champion, Leon R. Perrie, Sarah M. Beadel, Kerry A. Ford, Ilse Breitwieser, Ines Schönberger, Rowan Hindmarsh-Walls, Peter B. Heenan and Kate Ladley.
2012 | Not Threatened
Previous conservation statuses
2009 | Not Threatened
2004 | Not Threatened
Distribution
Indigenous. New Zealand: North, South, Stewart and Chatham Islands. Also Australia.
Habitat
Coastal to montane - but mostly found in coastal and lowland areas. A common plant of ponds, lake margins and slowly flowing streams. Also colonising roadside ditches. rarely found in muddy hollows within forest.
Features
Aquatic, submerged or floating, rhizomatous sparsely branched perennial herb. Rhizomes rooting at nodes and producing mostly simple leafy branches; these ultimately water surface. Stipules membranous, free, open. Leaves dimorphic. Submersed leaves usually rather distant, usually shortly petiolate; lamina c. 40–100 × 5–15 mm, narrowly elliptic, entire, subacute, delicate, ± translucent, longitudinal nerves c. 5–11, irregularly joined by cross veins. Floating leaves often long-petiolate; lamina 20–40 × 10–25 mm, broad oblong-oval, entire, usually quite obtuse, firm and opaque, longitudinal nerves 10–15, laterals emerging from petiole rather than from midrib. Inflorescence a densely flowered spike, 10-25 mm long. Peduncles in axils of floating leaves, stout, erect, usually projecting above surface of water at flower, submersed in fruit. Achene c.2.5 × 1.5 mm, green, green-brown or brown, moderately flattened with rather strongly 3-ridged keel and short straight beak.
Similar taxa
Distinguished from Potamogeton suboblongus by the strongly dimorphic foliage (i.e. clear distinction between submerged and emergent leaves), by the narrowly elliptic, ± translucent submerged leaves; floating leaves which are mostly broad-oval, with obtuse apices, and which have usually 6 or less (rarely an unequal higher number) nerves on either side of midrib; and by the green, green-brown or brown, flattened achenes which are 3-keeled when dry. In its submerged state Potamogeton cheesemanii could be confused with P. ochreatus from which it differs by non-fibrous stipules, and submerged and emergent elliptic to broadly oval leaves with well separated rather than closely set longitudinal nerves.
Flowering
November - March
Flower colours
Cream, Red/Pink
Fruiting
December - March
Propagation technique
Easily grown from rooted pieces and fresh seed, An attractive plant for a large pond or similar water body but inclined to become aggressive in fertile waters.
Etymology
potamogeton: River dweller
cheesemanii: Named after Thomas Frederick Cheeseman (1846 - 15 October 1923) who was a New Zealand botanist and naturalist who, in 1906, produced The Manual of the New Zealand Flora.
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.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Potamogeton cheesemanii Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/potamogeton-cheesemanii/ (Date website was queried)