Plate 1 figs. a–h · 4 observations
This species has been photographed under an open licence only 4 times, so some figures below are different views of the same plant, taken on the same day, rather than different individuals. They are usually different parts of it: the leaf, the flower, the bark.
Every figure is a research-grade observation under CC0, CC BY or CC BY-SA, rehosted with the photographer’s name, the licence and the observation it came from. Photographs under a NonCommercial licence are excluded from this site and are never stored, which costs us a great many pictures and is not negotiable.
Native range 124 botanical countries
Not drawn on the map: Kuril Is., Great Britain. We hold no public-domain boundary for these regions, so they are listed rather than guessed at.
Region boundaries approximated from Natural Earth (public domain) and mapped to TDWG World Geographical Scheme for Recording Plant Distributions (WGSRPD) level-3 botanical countries (Brummitt 2001). Indicative, not the official WGSRPD geometry.
Where it actually grows measured, from 239 observations
| Condition | 5th percentile | Median | 95th percentile |
|---|---|---|---|
| Coldest month, mean daily low | -21.2 °C | -10.7 °C | 1.5 °C |
| Warmest month, mean daily high | 17.7 °C | 23.4 °C | 28.2 °C |
| Annual rainfall | 481 mm | 802 mm | 1,428 mm |
| Rainfall in the driest quarter | 55 mm | 137 mm | 305 mm |
It is found where winters are severely cold. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 239 research-grade observations of Potamogeton berchtoldii that carry a coordinate, and this is the range those places actually span. The 5th and 95th percentiles are used rather than the minimum and maximum, because a single cultivated specimen in a heated conservatory should not widen a tropical plant's range to the Arctic.
This is not a hardiness zone. A USDA zone is the average annual extreme minimum temperature. The figure above is the mean daily minimum of the coldest month, which is a different quantity and is typically far warmer. Reading one as the other would place a plant several zones too warm, so we do not publish a hardiness zone, because we do not have one.
Also published as 35 synonyms
A synonym is not an error. It is a record of botanists disagreeing, in print, about where this plant belongs. Each of these was somebody’s considered answer.
- Potamogeton berchtoldii f. ramosissimus Fieber
- Potamogeton berchtoldii f. simplex Fieber
- Potamogeton berchtoldii subsp. tenuissimus (Mert. & W.D.J.Koch) Calder & Roy L.Taylor
- Potamogeton berchtoldii var. acuminatus Fieber
- Potamogeton berchtoldii var. berchtoldii
- Potamogeton berchtoldii var. colpophilus Fernald
- Potamogeton berchtoldii var. lacunatus (Hagstr.) Fernald
- Potamogeton berchtoldii var. major Nakai
- Potamogeton berchtoldii var. mucronatus Fielding
- Potamogeton berchtoldii var. mucronatus Fieber
- Potamogeton berchtoldii var. polyphyllus (Morong) Fernald
- Potamogeton berchtoldii var. tenuissimus (Mert. & W.D.J.Koch) Fernald
- Potamogeton clystocarpus Fernald
- Potamogeton fieberi Rouy
- Potamogeton gemmiparus (J.W.Robbins) Morong
- Potamogeton lacunatus Hagstr.
- Potamogeton lacunatus f. novae-angliae Hagstr.
- Potamogeton pusillus f. brevirostris Hagstr.
- Potamogeton pusillus f. pygmaeus Hagstr.
- Potamogeton pusillus f. tenuissimus (Mert. & W.D.J.Koch) Hagstr.
- Potamogeton pusillus prol. berchtoldii (Fieber) Rouy
- Potamogeton pusillus prol. tenuissimus (Hook.f.) Rouy
- Potamogeton pusillus subsp. gemmiparus (J.W.Robbins) R.R.Haynes & Hellq.
- Potamogeton pusillus subsp. tenuissimus (Mert. & W.D.J.Koch) R.R.Haynes & Hellq.
and 11 more.
Sourcesevery claim on this page
- World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
- iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.
- Wikidata. common name (P1843), joined on the World Flora Online identifier (P7715). CC0. Retrieved 2026-07-13.
- Kew, World Checklist of Vascular Plants (WCVP v16). native distribution by TDWG level-3 botanical country, and life form. CC BY 3.0. Retrieved 2026-06-04.
We publish what we can source and we say so when we cannot. This page has no care advice and no toxicity claim, because we do not yet have those from a source we can cite.