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

Solvin Zankl / Grass Snake (Natrix natrix) beside Marsh marigold flower in riverine habitat, Germany

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.

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

Ingo Arndt / Marsh marigold moth {Micropterix osthelderi} standing on a petal, Austria (One of the smallest lepidoptera in the world, wingspan around 2.5 mm)

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