Gary K. Smith / Southern marsh Orchid {Dactylorhiza praetermissa} growing on coastal dune slacks, Norfolk, UK, June

Gary K. Smith / Southern marsh Orchid {Dactylorhiza praetermissa} growing on coastal dune slacks, Norfolk, UK, June

WILLIAM OSBORN / Southern marsh orchid {Dactylorhiza praetermissa} Wales, UK

Simon Colmer / Close-up of flowers of Southern marsh orchid (Dactylorhiza praetermissa) Vale of Neath, South Wales

Simon Colmer / Southern Marsh Orchid (Dactylorhiza praetermissa) Vale of Neath, South Wales

Simon Colmer / Southern marsh orchid (Dactylorhiza praetermissa) Vale of Neath, south Wales, UK

Ross Hoddinott / Southern marsh orchid {Dactylorhiza praetermissa} Cornwall, UK

Geoff Simpson / Southern marsh orchid {Dactylorhiza praetermissa} Peak District, Derbyshire, UK

WILLIAM OSBORN / Group of four Southern marsh orchids {Dactylorhiza praetermissa} S. Glamorgan. Wales

Paul Harcourt Davies / Elder flower orchid (Dactylorhiza sambucina) yellow form, in flower with mountains in background, Campo Imperatore, Apennines, Abruzzo, Italy. April.

Paul Harcourt Davies / Roman orchid (Dactylorhiza romana) yellow form, in flower, Gargano, Puglia, Italy. April.

Paul Harcourt Davies / Roman orchid (Dactylorhiza romana) yellow form, in flower, Gargano, Puglia, Italy. April.

Paul Harcourt Davies / Wild tulips (Tulipa sylvestris australis and Tulipa australis) with magenta and yellow Elderflower orchids (Dactylorhiza sambucina) flowering at altitude above Piano Grande plateau, Sibillini National...

Paul Harcourt Davies / Elderflower orchid (Dactylorhiza sambucina) yellow and magenta varieties, in flower on mountainside, Sibillini, Umbria, Italy, May.

Paul Harcourt Davies / Elderflower orchid (Dactylorhiza sambucina) yellow and magenta varieties, in flower on mountainside, Sibillini, Umbria, Italy, May.

Paul Harcourt Davies / Elderflower orchid (Dactylorhiza sambucina) yellow variation, in flower on mountainside, Sibillini, Umbria, Italy. May.

Paul Harcourt Davies / Elderflower orchid (Dactylorhiza sambucina) yellow variation, in flower on mountainside, Sibillini, Umbria, Italy. May.

Paul Harcourt Davies / Marsh helleborine (Epipactis palustris) in flower, Sibillini, Le Marche, Italy. July.

Paul Harcourt Davies / Early marsh orchid (Dactylorhiza incarnata) in flower, Piediluco, Umbria, Italy. May.

Paul Harcourt Davies / Early marsh orchid (Dactylorhiza incarnata) in flower, Piediluco, Umbria, Italy. May.

Paul Harcourt Davies / Elderflower orchid (Dactylorhiza sambucina) an orchid of high mountains occurring in both yellow and magenta varieties, in flower, Campo Imperatore, Abruzzo, Italy. May.

Paul Harcourt Davies / Elderflower orchid (Dactylorhiza sambucina) an orchid of high mountains occurring in both yellow and magenta varieties, in flower, Campo Imperatore, Abruzzo, Italy. May.

Paul Harcourt Davies / Marsh helleborine (Epipactis palustris) in flower, Sibillini, Le Marche, Italy. July.

Paul Harcourt Davies / Elderflower orchid (Dactylorhiza sambucina) in flower on hillside, Puglia, Italy. June.

Paul Harcourt Davies / Two Elderflower orchids (Dactylorhiza sambucina) in varying colours, in flower, Sibillini, Umbria, Italy. May.

Paul Harcourt Davies / Elderflower orchid (Dactylorhiza sambucina) in flower, Sibillini, Umbria, Italy. May.

Nick Upton / Southern marsh orchid (Dactylorhiza praetermissa) flowering among Meadow buttercups (Ranunculus acris) near a flooded pool in a dune slack, Kenfig National Nature Reserve, Glamorgan, Wales, UK, June.

Michel Poinsignon / Southern marsh orchid (Dactylorhiza praetermissa) in flower, Lorraine, France. June.

Paul Harcourt Davies / Marsh helleborine (Epipactis palustris) in flower, Sibillini, Umbria, Italy. July.

Paul Harcourt Davies / Heath spotted-orchid (Dactylorhiza maculata saccifera) flower, Leonessa, Umbria, Italy. July.

Paul Harcourt Davies / Marsh helleborine (Epipactis palustris) in flower, Sibillini, Umbria, Italy. July.

Colin Varndell / Southern marsh orchids (Dactylorhiza praetermissa) flowering on roadside verge, Dorset, UK, June.

Colin Varndell / Southern marsh orchids (Dactylorhiza praetermissa) in bloom, Dorset, UK, June.

Bernard Castelein / Southern marsh orchid (Dactylorhiza praetermissa) flowers, Groot Schietveld, Wuustwezel, Belgium, June.

Will Watson / Common spotted orchid and Southern marsh orchid hybrid (Dactyloriza x grandis) in flower. Leicestershire, England, UK. Focus stacked.

Paul Harcourt Davies / Flecked marsh orchid (Dactylorhiza incarnata cruenta) at 2200m, lake in background. Valparola Pass, near Cortina, Dolomites, Belluno, Italy. July.

Paul Harcourt Davies / Frog orchid (Dactylorhiza viridis). Dolomites, Italy. June.

Paul Harcourt Davies / Frog orchid (Dactylorhiza viridis), close up. Dolomites, Italy. July.

Paul Harcourt Davies / Frog orchid (Dactylorhiza viridis). Dolomites, Italy. July.

Lorraine Bennery / Roman dactylorhiza (Dactylorhiza romana) Etna National Park, Sicily, April.

Lorraine Bennery / Orchid (Dactylorhiza markusii), Bosco della Ficuzza, Sicily, April.

Lorraine Bennery / Orchid (Dactylorhiza markusii), Bosco della Ficuzza, Sicily, April.

Linda Pitkin / Hybrid orchid, Common spotted orchid x Southern marsh orchid (Dactylorhiza fuchsii x praetermissa / Dactylorhiza x grandis) Hilltop, Kenley Common, Surrey, England, June.

Linda Pitkin / Southern marsh-orchid (Dactylorhiza praetermissa) Burpham Court Farm, Surrey, England, June.

Linda Pitkin / Southern marsh-orchid (Dactylorhiza praetermissa) in flower in meadow, Howell Hill SWT Nature Reserve, Surrey, England, June.