Alex Hyde / Jacob's Ladder (Polemonium caeruleum) flowering. Lathkill Dale NNR, Peak District National Park, UK, June.

Ole Jorgen Liodden / Boreal Jacobs-ladder (Polemonium boreale) in front dark mountains. Spitsbergen, Svalbard, July.

Wild Wonders of Europe / Liodden / Boreal jacobs ladder (Polemonium boreale) flowers, Spitsbergen, Svalbard, Norway, June 2009

Tim Fitzharris / Pointed Phlox (Phlox cuspidata) and Indian Paintbrushes (Castilleja miniata) in bloom, Hill Country, Texas

Tim Fitzharris / Broad-tailed Hummingbird (Selasphorus platycercus) feeding on Scarlet Gilia (Ipomopsis aggregata) flowers, New Mexico

Heather Angel / Cup and saucer plant (Cobaea scandens), bud and opening flower. Cultivated plant. Focused stacked.

Dave Bevan / Swallowtail (Papilio machaon) nectaring on Phlox (Phlox) flowers, Norfolk, England, UK, June.

Floris van Breugel / Tiny white flowers of Evening Snow (Linanthus dichotomus) opening up at twilight, Sierra Nevada, Alabama Hills, California, USA, March.

Mike Read / Rocky mountain phlox (Phlox nultiflora) Bear Tooth Pass, Wyoming, USA June

Kirkendall-Spring / North american phlox flowers (Phlox diffusa) in the Columbia National Wildlife Refuge, Washington, USA, April.

Bryan and Cherry Alexander / Boreal Jacob's Ladder (Polemonium boreale) in flower, Svalbard, Norway.

Pal Hermansen / Polar Jacob's ladder (Polemoninum boreale) in flower, Svalbard, Norway.