Terry Whittaker / Water vole (Arvicola amphibius) feeding on Yellow flag iris (Iris pseudacorus) seed pods, Kent, England, UK. October.

Dave Bevan / Female Four-spotted chaser (Libellula quadrimaculata) landing and taking off from a Yellow iris (Iris pseudacorus) flower, Norfolk, England, UK, June.

Juan Carlos Munoz / Yellow flag iris (Iris pseudacorus), Liendo, Cantabria, Spain. May.

Chris Mattison / Yellow Iris (Iris pseudacorus) open seedpod with seeds. Whitelye Common, Monmouthshire, Wales, UK, October

Terry Whittaker / Water vole (Arvicola amphibius) feeding on Yellow flag iris (Iris pseudacorus) seed pods, Kent, England, UK. October.

Terry Whittaker / Water vole (Arvicola amphibius) feeding on seed pods of Flag iris (Iris pseudacorus ), Kent, England, UK. October.

MYN / Dirk Funhoff / Yellow flag iris (Iris pseudacorus) showing reproductive parts, Büchelberg, Germany. Meetyourneighbours.net project.

MYN / Dirk Funhoff / Yellow flag iris (Iris pseudacorus), Büchelberg, Germany. Meetyourneighbours.net project.

MYN / Dirk Funhoff / Yellow flag iris (Iris pseudacorus), Büchelberg, Pfalz, Germany. May. Meetyourneighbours.net project

MYN / Dirk Funhoff / Yellow flag iris (Iris pseudacorus), Büchelberg, Pfalz, Germany. May. Meetyourneighbours.net project

Nick Upton / Teresa Sinclair watching a Short-haired bumblebee queen (Bombus subterraneus) nectaring on Yellow flag iris flowers (Iris pseudacorus) after releasing it during a UK reintroduction project run by the...

Nick Upton / Short-haired bumblebee queen (Bombus subterraneus) collected in Sweden nectaring on a Yellow flag iris flower (Iris pseudacorus) with its long tongue after release during a UK reintroduction project r...

Ross Hoddinott / Newly emerged Emperor dragonfly (Anax imperator) resting on Yellow iris (Iris pseudacorus) Broxwater, Cornwall, UK. June 2015.

Pascal Tordeux / Yellow flag iris (Iris pseudacorus) in pond with reflections of clouds, medicinal plant. France, May.

Pascal Tordeux / Yellow flag iris (Iris pseudacorus) not yet in flower, at pond edge, medicinal plant. France, April.

Chris Mattison / Flag iris (Iris pseudacorus) on black background. Focus stacked image.

Wild Wonders of Europe / della Ferrera / Yellow flag iris (Iris pseudacorus) in flower and Yellow water lily (Nuphar lutea) leaves on water, Hutovo Blato Nature Park, Bosnia and Herzegovina, May 2009

Wild Wonders of Europe / della Ferrera / Yellow flag iris (Iris pseudacorus) flowers and Yellow water lily (Nuphar lutea) leaves on water, with White willow (Salix alba) trees along a channel in the Hutovo Blato Nature Park, Bosnia and Herze...

Robin Chittenden / Iris sawfly (Rhadinoceraea micans) caterpillar on Flag Iris (Iris pseudacorus) leaf, Norfolk, England, UK. June.

Nigel Cattlin / Two Iris sawfly (Rhadinoceraea micans) larvae feeding on the leaves of a Yellow flag iris (Iris pseudacorus), Berkshire, UK. June.

Ross Hoddinott / Broad-bodied chaser dragonfly (Libellula depressa) resting on Yellow iris (Iris pseudacorus) leaves, Broxwater, Cornwall, UK, April.

Ashley Cooper / Ragged robin (Silene flos-cuculi), Orchids (Orchidaceae) and Yellow flag iris (Iris pseudacorus) flowering in a damp, marshy meadow, Ling Ness, South Nesting, Shetland, Scotland, UK. June.

Ashley Cooper / Yellow flag iris (Iris pseudacorus) beds at Upper Urafirth, Shetland, Scotland, UK. July.

Terry Whittaker / Common carder bee (Bombus pascuorum) enters frame and feeds on nectar from flag iris (Iris Pseudocorus) before leaving frame, Greater Manchester, June.

Terry Whittaker / Garden bumblebee (Bombus hortorum) feeding on nectar from flag iris (Iris Pseudocorus) before leaving frame, Greater Manchester, June.

Nick Upton / Yellow flag iris (Iris pseudacorus) and Common cottongrass (Eriophorum angustifolium) flowering in a damp meadow bordering Kenfig Pool, Kenfig National Nature Reserve, Glamorgan, Wales, UK, June.

Nick Upton / Yellow flag iris (Iris pseudacorus) clump flowering in a damp sand dune slack, Kenfig National Nature Reserve, Glamorgan, Wales, UK, June.

Nick Upton / Female Goldenrod crab spider (Misumena vatia) camouflaged on Yellow flag iris (Iris pseudacorus) flower waiting for prey to land, Kenfig National Nature Reserve, Glamorgan, Wales, UK, June.

Nick Upton / Goldenrod crab spider (Misumena vatia) female well camouflaged on a Yellow flag iris (Iris pseudacorus) flower as it waits for prey to land. Kenfig NNR, Glamorgan, Wales, UK, June.

Paul Harcourt Davies / Yellow flag iris (Iris pseudacorus) in flower near wetland, Umbria, Italy. May.

Ross Hoddinott / Scarce Chaser dragonfly (Libellula fulva) resting on Yellow Flag Iris flower bud (Iris pseudacorus), Lower Tamar Lakes, Cornwall, UK. May .

Ross Hoddinott / Scarce Chaser dragonfly (Libellula fulva) resting on Yellow Flag Iris flower bud (Iris pseudacorus), Lower Tamar Lakes, Cornwall, UK. May .

Ann & Steve Toon / Yellow flag iris (Iris pseudacorus), Northumberland National Park, UK, May

Ross Hoddinott / Beautiful demoiselle damselfly (Calopteryx virgo) female resting on Yellow iris (Iris pseudacorus) bud. Cornwall, England, UK. May.

Ross Hoddinott / Yellow iris (Iris pseudacorus). Cornwall, England, UK. May.

Linda Pitkin / Iris (Iris pseudacorus) flower and seed pod illustration.

Linda Pitkin / Yellow iris (Iris pseudacorus). River Thames Path, Hampton Court, Richmond Upon Thames, England, UK. May.

Ross Hoddinott / Male broad-bodied chaser (Libellula depressa) dragonfly resting on yellow flag iris flower bud (Iris pseudacorus), Broxwater, Cornwall, UK. May.

Ross Hoddinott / Four-spotted chaser dragionfly (Libellula quadrimaculata) dragonfly resting on Yellow Flag Iris flower bud (Iris pseudacorus), early morning, Broxwater, Cornwall, UK. May .

Will Watson / Yellow Iris (Iris pseudacorus), natural woodland pond, Shatsky National Natural Park, Volyn Oblast, Ukraine, May.