Hottonia palustrisL.

FeatherfoilWater Violetwater violet

WFO wfo-0000725040 Accepted WFO 2026-06 8 photographs CC0 / CC BY / CC BY-SA

Plate 1 figs. a–h · 8 separate observations

Hottonia palustris, photographed by snaily_naily
fig. a snaily_naily, CC BY 4.0 / 2022-06-13 / obs. 205763012

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.

The specimen a real sheet, in a real collection

Herbarium
Smithsonian, US National Herbarium
Accession
US 3663935
Filed as
Hottonia palustris L.
Det. by
Strong, Mark T., (BOT), Smithsonian Institution - National Museum of Natural History (UNITED STATES)
Collected
Collector illegible
Origin
DE
The sheet
View the digitised specimen (CC0 1.0)

A real pressed plant, in a real collection, under the accession number above. Not an illustration of one. The holding institution does not serve this sheet’s image to third parties, so there is no photograph here. The record is real and the link goes to it. Where we hold no openly licensed sheet for a species this section is simply absent, and where a sheet never recorded who determined it, that field stays empty rather than being filled in. Roughly half of all herbarium sheets never recorded a determiner, which is ordinary.

Native range 22 botanical countries

Regions where Hottonia palustris is native: Türkiye, Austria, Baltic States, Belarus, Belgium, Central European Russia, Czechia-Slovakia, Denmark, France, Germany, Great Britain, Hungary, Italy, Netherlands, Northwest European Russia, NW. Balkan Pen., Poland, Romania, South European Russia, Sweden, Switzerland, Ukraine TürkiyeAustriaBaltic StatesBelarusBelgiumCentral European RussiaCzechia-SlovakiaDenmarkFranceGermanyHungaryItalyNetherlandsNorthwest European RussiaNW. Balkan Pen.PolandRomaniaSouth European RussiaSwedenSwitzerlandUkraine
Native distribution of Hottonia palustris, after Kew’s World Checklist of Vascular Plants. Introduced, extinct and doubtful records are excluded, so this is where the plant is from, not everywhere it now grows.
RegionTDWG codeContinent
Austria AUT EUROPE
Baltic States BLT
Belarus BLR
Belgium BGM
Central European Russia RUC
Czechia-Slovakia CZE
Denmark DEN
France FRA
Germany GER
Great Britain GRB
Hungary HUN
Italy ITA
Netherlands NET
Northwest European Russia RUW
NW. Balkan Pen. YUG
Poland POL
Romania ROM
South European Russia RUS
Sweden SWE
Switzerland SWI
Ukraine UKR
Türkiye TUR ASIA-TEMPERATE

Not drawn on the map: Great Britain. We hold no public-domain boundary for this region, so it is 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.

Flowering 313 in flower of 422 examined

Proportion of examined Hottonia palustris in flower, by month
Month In flower Examined Share 95% interval
Jan 0 2 too few examined
Feb 0 3 too few examined
Mar 0 4 too few examined
Apr 42 52 81% 68% to 89%
May 190 196 97% 93% to 99%
Jun 77 88 88% 79% to 93%
Jul 3 12 25% 9% to 53%
Aug 1 21 5% 1% to 23%
Sep 0 26 0% 0% to 13%
Oct 0 11 0% 0% to 26%
Nov 0 5 0% 0% to 43%
Dec 0 2 too few examined

Peak flowering in May. Each bar is the share of Hottonia palustris observations in which someone actually recorded the reproductive state and found the plant in flower, not the raw number of flowering records. That distinction matters: people observe plants far more in spring than in winter, so a bare count of flowering records partly measures when people go outside. Dividing by the number examined removes that. 313 of 422 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 4 months have fewer than 5 examined observations, so no proportion is drawn for them. This is still a global aggregate and not a forecast for your garden: the same species flowers on different dates in different hemispheres. Where a species has fewer than 30 flowering records we do not draw this chart at all. Computed from 10.15468/dl.cgje2x.

Where it actually grows measured, from 2,014 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -10.0 °C -1.7 °C 2.0 °C
Warmest month, mean daily high 19.3 °C 22.3 °C 25.7 °C
Annual rainfall 567 mm 689 mm 1,087 mm
Rainfall in the driest quarter 95 mm 126 mm 195 mm

It is found where winters bring hard frost. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 2,014 research-grade observations of Hottonia palustris 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. Climate from CHELSA V2.1 (Karger et al. 2017); occurrences from 10.15468/dl.cgje2x.

Also published as 4 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.

  • Androsace aquatica [Clairv.]
  • Breviglandium palustre Dulac
  • Hottonia millefolium Gilib.
  • Hottonia palustris var. rosea Gray

Sourcesevery claim on this page

  1. World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
  2. iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.
  3. Wikidata. common name (P1843), joined on the World Flora Online identifier (P7715). CC0. Retrieved 2026-07-13.
  4. 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.