Felis Images / Primrose (Primula sikkimensis) flowers, Bhutan.

Felis Images / Flowers (Impatiens stenantha) West Bengal, India.

Felis Images / Primrose (Primula sp) flower, Chele La, Bhutan.

Felis Images / Panicled yellow poppy (Meconopsis paniculata) growing on rocky ground, Sikkim, India.

Felis Images / Dendrobium orchids (Dendrobium thyrsiflorum) West Bengal, India.

Felis Images / Dendrobium orchids (Dendrobium thyrsiflorum) West Bengal, India.

Felis Images / Dendrobium orchid flowers (Dendrobium fimbriatum) Singalila National Park, West Bengal, India.

Felis Images / Touch-me-not (Impatiens falcifer) flower, Sikkim, India.

Felis Images / Panicled yellow poppy (Meconopsis paniculata) growing on rocky ground, Sikkim, India.

Felis Images / Sikkim cowslip (Primula sikkimensis) Chelela, Bhutan.

Colin Varndell / Golden samphire (Inula crithmoides) flower. Portland, Dorset, UK July.

Nick Upton / Coastal ragwort (Senecio leucanthemifolius falcifolius) flowering on bare coastal headland, Bahia de La Pared, Fuerteventura, Canary Islands, May.

Nick Upton / Canary Island Daisy (Asteriscus sericeus / Nauplius sericeus), a Fuertventura endemic, flowering in a clump on an exposed, misty mountain top, near Betancuria, Fuerteventura, Canary Islands, June.

Nick Upton / Canary Island Daisy (Asteriscus sericeus / Nauplius sericeus), a Fuertventura endemic, flowering on an exposed mountain top, near Betancuria, Fuerteventura, Canary Islands, June.

Kim Taylor / Cypress spurge (Euphorbia cyperissias), Apennines, Italy. Apennines, Italy, May.

Mike Read / Scots elm (Ulmus glabra) in flower beside the Abhainn na Coinnich river, Kingairloch Estate, Highlands, Scotland, UK. May.

SCOTLAND: The Big Picture / Silver birch (Betula pendula) golden leaves in autumn leaves, Scotland, UK. October.

Nick Upton / European birthwort / Dutchman's pipe (Aristolochia clematitis) in flower, Merthyr Mawr Warren National Nature Reserve, Glamorgan, Wales, UK. May.

Nick Upton / European birthwort / Dutchman's pipe (Aristolochia clematitis) flowering by a marshy stream through coastal sand dunes, Merthyr Mawr Warren National Nature Reserve, Glamorgan, Wales, UK. May.

Nick Upton / Close up of Sea spurge (Euphorbia paralias) flowering, Merthyr Mawr Warren National Nature Reserve, Glamorgan, Wales, UK. July.

Nick Upton / Sea spurge (Euphorbia paralias) flowering on coastal sand dunes just above the shore line, Merthyr Mawr Warren National Nature Reserve, Glamorgan, Wales, UK. July.

Nick Upton / Sea spurge (Euphorbia paralias) flowering on coastal sand dunes just above the shore line, Merthyr Mawr Warren National Nature Reserve, Glamorgan, Wales, UK. July.

Nick Upton / Portland spurge (Euphorbia portlandica) flowering on coastal sand dunes, Merthyr Mawr Warren National Nature Reserve, Glamorgan, Wales, UK. April.

Nick Upton / Mouse-ear hawkweed (Pilosella officinarum) flowering on coastal sand dunes in spring, Merthyr Mawr Warren National Nature Reserve, Glamorgan, Wales, UK. May.

Nick Garbutt / Turning European beech (Fagus sylvatica) woodland in autumn, Exmoor National Park, Somerset / Devon, England. November.

Alan Williams / Crocus (Crocus sp.) in flower, Willaston village, Wirral, Cheshire, UK. February.

Robert Thompson / Trumpet lily (Lilium 'Yellow Planet') close-up of stamens, County Down, Northern Ireland. August.

Linda Pitkin / Hoary Ragwort (Senecio erucifolius) in flower, Surrey, England. August.

Linda Pitkin / Hoary Ragwort (Senecio erucifolius) in flower, Surrey, England. August.

Linda Pitkin / Common primrose (Primula vulgaris) in flower, Surrey, England. March.

Linda Pitkin / Lesser celandine (Ranunculus ficaria) in flower, Surrey, England. March.

Linda Pitkin / Coltsfoot (Tussilago farfara) flowers opening, Surrey, England. March.

Linda Pitkin / Goldilocks buttercup (Ranunculus auricomus) in flower, Surrey, England. May.

Linda Pitkin / Crosswort (Cruciata laevipes) in flower, Hutchinson's Bank Nature Reserve, Surrey, England. May.

Konrad Wothe / Coltsfoot (Tussilago farfara) flowering, Bavaria, Germany, Europe. April.

Paul Harcourt Davies / Autumn Downy oak (Quercus pubescens) leaves, Tuscany, Italy. October.

Paul Harcourt Davies / Autumn leaf of Chinese wisteria (Wisteria sinensis), Umbria, Italy. October.

Paul Harcourt Davies / Mediterranean lineseed (Bellardia trixago), semi-parasitic on grasses, in flower, Umbria, Italy, May.

Paul Harcourt Davies / Greater milkwort (Polygala major) in flower in alpine turf and rocks, Gran Sasso, Abruzzo, Italy. June.

Paul Harcourt Davies / Hoary rockrose (Helianthemum oelandicum) in flower, Sibillini, Umbria, Italy. May.

Philippe Clement / Common honeysuckle / European honeysuckle (Lonicera periclymenum) in flower, Belgium, June.

Philippe Clement / Tansy / Common tansy (Tanacetum vulgare) in flower, Belgium. August.

Doug Gimesy / Australian banyan / Moreton Bay fig (Ficus macrophylla) fruit close up, Brighton, Victoria, Australia. Cropped.

John Waters / Bee orchid (Ophrys apifera) among flower-rich grassland, Daneway Banks, Stroud, Gloucestershire, UK, June.