Water Violet, Hottonia palustris

Latin Name: Hottonia palustris

Common Name: Water Violet (Water-violet)

Other Common Names: Featherfoil, Water Featherfoil, Water Gilliflower, Water Milfoil

Local Names: Cat’s Eyes, Cuckoo Flower (Somerset); Water Yarrow (Yorkshire).

Plant Family: Primulaceae

QUICK FACTS:

• Native, perennial, fast-growing, lowland aquatic plant
• Plant with submerged vegetation and erect flower spikes that appear on long, round stems above the waterline between May and June
• 5-petalled, pale lilac/pink/white flower with yellow eyes in whorls at intervals towards the top of the stem
• Calyx split into 5 narrow sepals
• Deeply-divided, feather-like leaves are generally submerged, but can appear in whorls on the surface in dry conditions
• Roots loosely and centrally in shallow bottom of ditches and ponds. Some silvery roots float freely in the water.

HABITAT:

Low-lying, inland wetlands. Shallow, clear, unpolluted, still or slow-moving base-rich water, ditches, dykes, ponds and rhynes. Thrives in water rich in calcium and with moderate levels of nutrients.

UK DISTRIBUTION:

Scattered in England. More common in East and North-east. Rare in Wales. Rare in Ireland, where some sites are introductions. Only 12 records on NBN Atlas for Scotland. Nationally in decline, but can be locally common.

Many colonies were lost before 1930. Losses have continued in the South-east. These are largely due to drainage, vegetation clearance, eutrophication, boat traffic and trampling by cattle according to the Online Atlas of the British and Irish Flora.

National Biodiversity Network Distribution map link.

SOMERSET DISTRIBUTION:

2020 – VC5: Not Scarce; VC6: Not Scarce

Locally common on the Levels but a declining species due to changing farming practices which permit the rhynes to become choked with vegetation (Green Brothers 1997).

The national decline has been less noticeable in Somerset, although it appears to have been lost from sites at the edge of its distribution, particularly in the West.

VC5: only ever recorded on the Levels, where it is notably found in SSSIs.

VC6: its stronghold is also on the Levels. (Crouch 2018)

THREATS:

• Very susceptible to water pollution
• Threatened by habitat loss, drainage and poor management
• Increased salinity
• Extended periods of drought

CONSERVATION STATUS:

• IUCN – Least Concern (LC)
• Great Britain Red List – Least Concern (LC)
• England Red List – Vulnerable (VU)
• Northern Ireland – Protected plant under Article 14(1) (a) and (2) of the Wildlife (Northern Ireland) Order 1985, Part 1.
• Croatia and Switzerland – Endangered (EN)
• France – Protected plant status in 6 French regions.
• Link to Kew Science’s Global distribution map on Plants of the World Online showing Native, Introduced and Extinct areas.

BIODIVERSITY SUPPORT:

• Oxygenates water for other aquatic species
• Bushy leaves provide protection for fish and fry
• Habitat for water snails and invertebrates

OTHER REMARKS:

• Oxygenating plant sometimes sold for garden ponds, but not a common choice by gardeners, horticulturalists and landscapers.
• Highly intolerant of salinity. Increased potential threat under climate change?
• Last Great Britain review showed 53% decline in area of occupancy and 37% decline in extent of occurrence (Stroh et al.)
• Resting buds overwinter by sinking to the bottom of the water.
• Able to survive in short, dry periods out of water. Leaves become more rigid.
• Prefers sunny locations. Can withstand shade and temporary exposure.

Gallery of Plant and Habitat Images

Left to right from top – Fig. 1: Close-up of Hottonia palustris flower; Fig. 2: Habitat of Hottonia palustris in shallow, water-filled ditch near Wedmore, Somerset; Fig. 3: Whorled flower spike of Hottonia palustris; Fig. 4: Examining leaves of Hottonia palustris out of the water with water snails and insects; Fig. 5: Public domain botanical drawing of Hottonia palustris; Fig. 6: Hottonia palustris as far as the eye can see in Somerset rhyne viewed from roadside between Wedmore and Draycott; Fig 7: Closer shot of same view.

All photos: © Karen Andrews

It cannot be said too often that it is as much the conservationist’s job to keep common species common as it is to ensure the survival of rare species.

N. W. Moore (1987)

Further Details

Plant Naming

Binomial: Hottonia palustris L.

Genus: Hottonia named by Linnaeus after Dutch Botanist, Petrus Houttuyn (1648-1709). (This is distinctly separate from the genus Houttuynia in Saururaceae named after the zoologist Martinus (Maarten) Willem Houttuyn (1720-1798)).

Epithet: palustris means of marshland.

Other Language Common Names:

French: Hottonie des marais, Millefeuille aquatique, Millefeuille d’eau.

German: Vaterviolier, Wasserfeder.

Italian: Erba scopina, Fertro.

Spanish: Pluma acuática.

Reproduction:

• Hermaphrodite: both male and female organs
• Pin-eyed and thrum-eyed flowers like Primrose, Primula vulgaris. Heterostylous, requiring crosses between pins and thrums to set seed.
• Open flowers pollinated by insects
• Cleistogamy: self-pollinates some flowers without ever opening. Self-fertile.
• Propagation by seed or division.
• Vegetative growth often produced single-morph colonies that set little seed.
• Fruit is a globular/spherical capsule that splits.
• Link to Global Pollen Project images

Morphology Illustrations

(Links or images to be inserted)

Under the Microscope:

(Microscope images or relevant links to be inserted)

Hazards:

No known hazards.

Medicinal Uses:

Limited usage. Herbal remedy. (See Kew Science Medicinal Plant Names Services for further links and information).

Cultural References:

No known symbolic, historical or mythological references. No known role in cultural customs of UK or other countries.

Postage Stamps

Hottonia palustris has featured in stamp collections in the following countries:

Germany: First day issue 8 October 1981 for Red-listed bog, wet meadow and aquatic plants: Hottonia palustris (Wasserfeder > Water Violet) 60 DM 30 Pfennigs; Trapa natans (Wassernuss > Water Chestnut) 40 DM 20 Pfennigs; Nymphoides peltata (Seekanne > Fringed Water Lily) 50 DM 25 Pfennigs; Lobelia dortmanna (Wasserlobelie > Dortmann’s Cardinalflower, Water Lobelia) 90 DM 45 Pfennigs.

Romania: 1996 Water Flora collection: Hottonia palustris L. 5 Bani; Ceratophyllum submersum L. 10 Bani; Aldrovanda vesiculosa L. (Waterwheel Plant) 20 Bani; Callitriche verna L. (Star Grass, Water Starwort) 40 Bani; Vallisneria spiralis L. (Straight Vallisnera, Tape Grass, Eel Grass) 55 Bani; Elodea canadensis Rich. (American Waterweed, Canadian Waterweed or Canadian Pondweed) 1 Leu; Myriophyllum spicatum L. (Spiked Water Milfoil) 3.25 Lei; (species for 1.55 Lei Unknown).

© Karen Andrews

References and Further Reading

• BBC (2014): Water Violet. Gardening. Plant Finder. (Archived. No longer updated).
• BSBI (2019): Hottonia palustris. Online Atlas of the British and Irish Flora.
• Crouch, H. J. (2018): Hottonia palustris L. Water Violet. Somerset Rare Plant Register Account. 2 March 2018.
• Devon Biodiversity Action Plan (?): Primrose.
• European Environment Agency (2019): Hottonia palustris L. EUNIS Home.
• Freshwater Habitats Trust (?): Water Violet.
• Green, Paul R. & Green, Ian P. & Crouch, Geraldine A. (1997): The Atlas Flora of Somerset. (self-published).
• Grigson, Geoffrey (1996): The Englishman’s Flora. Helicon.
• Hackney, Paul (2006-18): Priority Species. Hottonia palustris, Water-violet. Northern Ireland National Museums.
• Harrap, Simon (2013): Harrap’s Wild Flowers. A Field Guide to the Wild Flowers of Britain & Ireland. Bloomsbury. London.
• IUCN (2020): IUCN Red List of Threatened Species. (Scroll down to Categories and Criteria).
• Jain S.K. (1990): Conservation of aquatic plants. In: Gopal B. (eds) Ecology and management of aquatic vegetation in the Indian subcontinent. Geobotany, vol 16. Springer, Dordrecht
• Kew Science (2020): Hottonia palustris L. Plants of the World Online.
• Lansdown, R.V. (2014) Hottonia palustris. The IUCN Red List of Threatened Species 2014: e.T167912A42402679. https://dx.doi.org/10.2305/IUCN.UK.2014-1.RLTS.T167912A42402679.en.
• Legislation.gov.uk (1985): The Wildlife (Northern Ireland) Order 1985.
• Lilies Water Gardens (2020): Hottonia palustris.
• National Biodiversity Network (2017): Hottonia palustris L.: Water Violet. NBN Atlas.
• Natural History Museum (1998?): Hottonia palustris L. – Water-Violet.
• People Pill (): Petrus Houttuyn: Dutch Botanist.
• Plantlife (2020): Water-violet, Hottonia palustris.
• Plants for a Future (2010-20): Hottonia palustris – L. PFAF Plant Database.
• Puddleplants (2020): Water Violet (Hottonia palustris). .
• RHS (2020): Hottonia palustris. RHS Gardening.
• Shoot Gardening (2004-20): Hottonia palustris (Water Violet).
• Somerset Rare Plant Group (2020): Rare Plant Register.
• Stace, Clive (2010): New Flora of the British Isles. Third Edition. Cambridge University Press.
• Streeter, David et al. (2016) Collins Wild Flower Guide. 2nd Edition. The Most Complete Guide to the Wild Flowers of Britain and Ireland. William Collins. London.
• Stroh, P. et al. (?): A Vascular Plant Red List for England. BSBI.
• Stroh, P. et al. (2014): GB Red List for vascular plants. Revised February 2019. BSBI.
• Tele Botanica (2020?): Hottonie des marais, Hottonia palustris L. Primulaceae. eFlore.
• Thomé, Prof. Dr. Otto Wilhelm (1885): Public Domain image of Hottonia palustris from Flora von Deutschland, Österreich und der Schweiz 
• Webster, Margaret (2017): The Primula S Locus. Thrums, pins, and homostyles. Primula breeding system. SPRG.
• Wild Flower Finder (2018): Water Violet.

Copyright Note

Karen does not seek or receive any commercial interest or advantage from this blog. She is not promoting any business venture. She simply loves to share fascinating facts about plants. These pages illustrate her love of plants, botany, biodiversity, gardens and creative expression. There is always so much to learn about plant diversity. This blog is designed as a showcase for photography, commentary on plants and wildlife, gardens and other places visited, horticulture and related topics. Viewpoints are her own, not those of her employer.

© Karen Andrews 2018 onwards. All rights reserved. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Karen Andrews and BotanyKaren.net with appropriate and specific direction to the original content.