Sven Zacek / March Marigolds (Caltha palustris) in flower in wetland woodland floor. Estonia, Europe, May.

WILLIAM OSBORN / King cup flowers / Marsh marigold {Caltha palustris} Gloucestershire, UK

Heather Angel / Wasp nectaring on Marsh marigold (Caltha palustris), picking up pollen on head, thorax and hairs on body. Turkey. May.

David Woodfall / Ancient stone bridge over stream running through machair ,with abundant Marsh marigholds (Caltha palustris) North Uist, Scotland, UK, June.

Sven Zacek / Marsh marigold (Caltha palustris) flowering in swamp forest. Tartumaa, Southern Estonia. May.

Sven Zacek / Marsh marigold (Caltha palustris) flowering in swamp forest. Lahemaa National Park, Harjumaa, Northern Estonia. May.

Sven Zacek / Marsh marigold (Caltha palustris) flowering along Altja river, Lahemaa National Park, Laane-Virumaa, Northern Estonia. May.

Colin Varndell / Marsh marigold (Caltha palustris) flower. Dorset, UK May.

Jouan Rius / Claret Cup Cactus in flower (Echinocereus triglochidiatus), Capitol Reef National Park, Utah, USA, April.

Gary K. Smith / Marsh-marigold (Caltha palustris) in flower.

Jack Dykinga / Claret Cup cactus (Echinocereus triglochidiatus) and fallen Agave (Agave utahesis) flowers, Grand Canyon-Parashant National Monument, Arizona, USA.

Rolf Nussbaumer / Claret Cup Cactus (Echinocereus triglochidiatus), flower, Hill Country, Texas, USA. April

Nick Garbutt / Marsh marigolds (Caltha palustris) in flower. Nordtirol, Tirol, Austrian Alps, Austria, July.

Nick Turner / Marsh marigold / King cup (Caltha palustris) flowering by a marshy stream on the Limestone Link trail, St.Catherine Valley, South Gloucestershire, UK. April 2015.

Nick Turner / Marsh marigold / King cup (Caltha palustris) flowering by marshy stream on the Limestone Link trail, St.Catherine Valley, South Gloucestershire, UK. April 2015.

Nick Turner / Marsh marigold / King cup (Caltha palustris) flowering on Limestone Link trail, St.Catherine Valley, South Gloucestershire, UK. April.

Nick Turner / Marsh marigold / King cup (Caltha palustris) flowering by marshy stream on Limestone Link trail, St.Catherine Valley, South Gloucestershire, UK. April.

Stephen Dalton / Kingcups or Marsh marigold (Caltha palustris) Sussex, UK

Mike Read / Marsh marigold (Caltha palustris) close up of flower, water meadows in Ringwood, Hampshire, UK May

Mike Read / Marsh marigold (Caltha palustris) flowering in water meadows, Ringwood, Hampshire, UK May

Mike Read / Water avens (Geum rivale) Cuckoo flower (Cardamine pratensis) and Marsh marigold (Caltha palustris) flowering in water meadow, Ringwood, Hampshire, UK April

John Waters / Marsh marigold (Caltha palustris) flowering in damp woodland on the Mendip Hills, Somerset, UK, April.

Alex Hyde / Marsh Marigold (Caltha palustris) in flower, River Wye, Monsal Dale, Peak Distict National Park, Derbyshire, UK. May.

Pascal Tordeux / Marsh marigold (Caltha palustris) in flower, medicinal plant, Queyras, France, June.

Wild Wonders of Europe / Widstrand / Marsh marigold / King's Cup (Caltha palustris) Linden Tree Retreat & Ranch, Velika Plana, Velebit Mountains Nature Park, Croatia, April 2014.

Willem Kolvoort / Marsh marigold (Caltha palustris) along bank of brook, North Holland. April.

Willem Kolvoort / Marsh marigold (Caltha palustris) along bank of brook, North Holland. May.

Willem Kolvoort / Marsh marigold (Caltha palustris) with Mannagrass (Glyceria fluitans) and Common water crowfoot (Ranunculus aquatilis) along brook, North Holland. April.

Willem Kolvoort / Marsh marigold (Caltha palustris) with Mannagrass (Glyceria fluitans) and Common water crowfoot (Ranunculus aquatilis) along brook with seep inflow, North Holland. April.

Rod Williams / Marsh Marigolds (Caltha palustris) WWT London Wetland Centre, Barn Elms, Barnes, London, England, UK, Late March

Fabrice Cahez / Marsh marigold / Kingcup (Caltha palustris) Vosges, France, April.

Fabrice Cahez / Marsh marigold / Kingcup (Caltha palustris) Vosges, France, April.

Fabrice Cahez / Marsh marigold / Kingcup (Caltha palustris) Vosges, France, April.

Fabrice Cahez / Marsh marigold / Kingcup (Caltha palustris) Vosges, France, April.

Fabrice Cahez / Marsh marigold / Kingcup (Caltha palustris) Vosges, France, April.

Zoltan Nagy / Marsh marigold (Caltha palustris) Retezat Mountains, Romania. June

Fabrice Cahez / Small waterfall in spring with Kingcup (Caltha palustris) Vosges mountains, France, May

Sven Zacek / Marsh marigold (Caltha palustris) in bloom at the edge of a forest river, Northern Estonia, May.

Sven Zacek / Marsh marigold (Caltha palustris) in bloom at the edge of a forest river, Northern Estonia, May.

Stephen Dalton / Kingcups or Marsh marigolds (Caltha palustris) Rookery Pond, Sussex, April

Stephen Dalton / Kingcups or Marsh marigolds (Caltha palustris) Rookery Pond, Sussex, April

Sandra Bartocha / Marsh Marigold (Caltha palustris) flowering in Alder carr Mecklenburg-Vorpommern, Germany, April

Linda Pitkin / 2020VISION / Marsh Marigold (Caltha palustris), on bank of River Itchen, seen below rippled surface. Ovington, Hampshire, England, May. Did you know? The Marsh marigold is one of the UK's most ancient native plant...

Stephen Dalton / Kingcup / Marsh marigold (Caltha palustris) flowering beside water, UK, April

MYN / Marko Masterl / Marsh marigold (Caltha palustris) in flower, wet woodlands, Kocevje, Slovenia, Europe, April. meetyourneighbours.net project

Hanne & Jens Eriksen / Marsh marigolds (Caltha palustris) flowering, Iceland, June

Philippe Clement / Kingcup / Marsh Marigold (Caltha palustris) in flower. Luxembourg, April.

Philippe Clement / Kingcup / Marsh Marigold (Caltha palustris) in flower. Luxembourg, April.

Stephen Dalton / Kingcup / Marsh Marigold (Caltha palustris) by water. Sussex, UK, April.

Nick Upton / Marsh marigold / King cup (Caltha palustris) clump flowering near the margins of a stream. Wiltshire, UK, April.

Nick Upton / Marsh marigold / King cup (Caltha palustris) clump flowering near the margins of a stream. Wiltshire, UK, April.

Stephen Dalton / Marsh marigold / Kingcup (Caltha palustris) flowers, UK

Chris Gomersall / Marsh marigolds / Kingcups (Caltha palustris) in flower, Wiltshire, April

Chris Gomersall / Marsh marigolds / Kingcups (Caltha palustris) in flower, Wiltshire, April

Robert Thompson / Marsh marigold {Caltha palustris} flowers, Correl Glen NNR, County Fermanagh, Northern Ireland, UK

Roger Powell / Marsh Marigold {Caltha palustris} flowering in old snow melt areas of Honoya island, Varanger, Norway

Andy Sands / Marsh Marigolds (Caltha palustris) with old farming equipment, Holwick Fell, Upper Teesdale, Co Durham, England. UK

Bruno D'Amicis / Marsh marigold (Caltha palustris) in flooded forest. Poland

Niall Benvie / King cups {Caltha palustris} in wetlands with tree reflections in water, Kemeri NP, Latvia

Niall Benvie / King cup / Marsh marigold {Caltha palustris} Otterpark Aqualutra, Leeuwarden, Netherlands

Niall Benvie / King cups {Caltha palustris} in Black alder carr Kemeri NP, Latvia

Bernard Castelein / Marsh marigold flowers (Caltha palustris) Belgium

Bernard Castelein / Marsh marigold (Caltha palustris) flowering in wetlands, Belgium

Willem Kolvoort / Marsh marigold in flower (Caltha palustris) Holland

Simon Colmer / Marsh marigold flower (Caltha palustris) UK

Philippe Clement / Marsh marigolds / King cups {Caltha palustris} with {Senecio sp} in seed in broadleaf forest, Germany

Philippe Clement / Marsh marigolds / King cups {Caltha palustris} with {Senecio sp} in broadleaf forest, Germany

Kim Taylor / Sunfly / hoverfly {Helophilus pendulus} pollinates Kingcup flower, UK.

Kim Taylor / Sunfly / hoverfly {Helophilus pendulus} pollinates Kingcup flower, UK.

Philippe Clement / Marsh marigold / Kingcup in flower {Caltha palustris} Belgium

Philippe Clement / Marsh marigold / Kingcup in flower {Caltha palustris} Belgium

Rob Tilley / King cup / Marsh marigold flowers {Caltha palustris} Hokkaido, Japan

Pal Hermansen / Marsh marigolds (Caltha palustris) in flower, Ski, Norway. May.

Ashley Cooper / Two flies collecting pollen from Marsh marigold (Caltha palustris) in a garden pond, Ambleside, Lake District, Cumbria, UK. April.

Jack Dykinga / Claret cup cactus (Echinocereus triglochidiatus) in flower, Santa Catalina foothills, Sonoran Desert, near Tucson, Arizona, USA. August.

Jack Dykinga / Claret cup cactus (Echinocereus triglochidiatus) in flower, Santa Catalina foothills, Sonoran Desert, near Tucson, Arizona, USA. August.

Paul Harcourt Davies / Marsh marigold / Kingcup (Caltha palustris) in flower on wet ground, Abetone, Emilia Romagna, Italy. June.

Paul Harcourt Davies / Marsh marigold / Kingcup (Caltha palustris) in flower on wet ground, Abetone, Emilia Romagna, Italy. June.

Paul Harcourt Davies / Marsh marigold / Kingcup (Caltha palustris) flowering on mountainside, Abetone, Emilia Romagna, Italy. June.

Paul Harcourt Davies / Marsh marigold / Kingcup (Caltha palustris) in flower next to mountain stream, Abetone, Emilia Romagna, Italy. June.

Paul Harcourt Davies / Marsh marigold / Kingcup (Caltha palustris) in flower next to mountain stream, Abetone, Emilia Romagna, Italy. June.

Terry Whittaker / White tailed bumblebee (Bombus lucorum) flies to Marsh marigold (Caltha palustris) flower and feeds on nectar from before leaving frame, Greater Manchester, September.

Terry Whittaker / Marmalade hoverfly (Episyrphus balteatus) feeds on nectar from a Marsh marigold (Caltha palustris), Greater Manchester, September.

Terry Whittaker / Marmalade hoverfly (Episyrphus balteatus) feeds on nectar from a Marsh marigold (Caltha palustris), Greater Manchester, September.

Adrian Davies / Marsh marigold (Caltha palustris) in flower on the banks of a waterfall. April.

Guy Edwardes / Marsh marigolds (Caltha palustris) flowering in front of Newton Mill, near River Stour, Dorset, UK. May.

Linda Pitkin / Marsh-marigold (Caltha palustris) in flower, Surrey, England. April.

Linda Pitkin / Close up of Marsh-marigold (Caltha palustris) flower, Surrey, England. April.

Linda Pitkin / Close up of Marsh-marigold (Caltha palustris) flower, Surrey, England. April.

John Waters / Wet pasture with Marsh marigold (Caltha palustris), Island of Egilsay, Orkney, Scotland, UK, May 2021.

Linda Pitkin / Marsh-marigold (Caltha palustris) watercolour painting

Robin Chittenden / Marsh marigold (Caltha palustris). Norfolk, England, UK. April.

John Waters / Marsh Marigold (Caltha palustris) with Drone fly (Eristalis tenax) active in background, Bristol, UK, March.

John Waters / Drone fly (Eristalis tenax) on flower of Marsh Marigold (Caltha palustris), Bristol, UK, March.

John Waters / Drone fly (Eristalis tenax) on flower of Marsh Marigold (Caltha palustris), Bristol, UK, March.

Paul Harcourt Davies / Marsh marigold (Caltha palustris) at edge of rocky strream. Sella massif, Dolomites, Italy. June.