Chris Mattison / Stigma and anthers of Cactus flower (Notocactus crassigibbus). Cultivated plant. Focus-stacked image.

Gabriel Rojo / Close up of Passionflower (Passiflora caerulea) La Pampa, Argentina.

Stephen Dalton / Close up of the inside of a foxglove (Digitalis purpurea) showing the pistil and stamen, UK.

Wild Wonders of Europe / Bartocha / Common peony (Paeonia officinalis) close up of stamens and stigma, Monti Sibillini National Park, Italy, May.

Paul Harcourt Davies,Paul Harcourt Davies / Martagon lily (Lilium martagonium) flower, Terminillo, Rieti, Lazio, Italy, July

Rolf Nussbaumer / Texan spider lily (Hymenocallis liriosme) stamens close up, Texas Coast, USA

Wild Wonders of Europe / Lilja / Tulips (Tulipa bakeri) close-up of flowers, Omalos, Crete, Greece, April 2009

Wild Wonders of Europe / Shpilenok / Close-up inside Wild tulip (Tulipa schrenkii, ) Rostovsky Nature Reserve, Rostov Region, Russia, April 2009

Wild Wonders of Europe / Widstrand / Close-up of Poppy flower stamens and stigma, La Serena, Extremadura, Spain, April 2009

Wild Wonders of Europe / Schandy / Anemone sp flower, close up of stamens, Mount Cheget, Caucasus, Russia, June 2008

Wild Wonders of Europe / Döerr / Meadow Saffron flower (Colchicum autumnale) soft focus, Piatra Craiului Mountains, Transylvania, Southern Carpathian Mountains, Romania, October 2008

Wild Wonders of Europe / Döerr / Meadow Saffron flower (Colchicum autumnale) soft focus, Piatra Craiului Mountains, Transylvania, Southern Carpathian Mountains, Romania, October 2008

Rolf Nussbaumer / Lace Cactus {Echinocereus reichenbachii} flower abstract, Texas, USA

Kim Taylor / Herb Robert {Geranium robertianum} close-up of stamen and anthers, showing pollen grains, Surrey, England.

Mark Moffett / Flower Mantis (Creobroter sp) nymph blending in with plant stamens, Myanmar

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

Robert Thompson / Yellow loosestrife (Lysimachia punctata) close up of stamens, County Down, Northern Ireland. July.

Robert Thompson / Passion flower (Passiflora caerulea) stamen detail, Banbridge, County Down, Northern Ireland. April.

Robert Thompson / Hawthorn (Crataegus laevigata) flowers, Brackagh Moss National Nature Reserve, County Armagh, Northern Ireland. May.

Robert Thompson / Greater stitchwort (Stellaria holostea) stamen detail, Brackagh Moss National Nature Reserve, County Armagh, Northern Ireland. April.

Paul Harcourt Davies / Nettle-leaved bellflower (Campanula trachelium) in flower, Lazio, Italy. July.

Paul Harcourt Davies / Rattlesnake root purple lettuce (Prenanthes purpurea) in flower, Tuscany, Italy. July.

Paul Harcourt Davies / Dog rose (Rosa canina) in flower, Podere Montecucco Garden, Umbria, Italy. June.

Paul Harcourt Davies / Dog rose (Rosa canina) in flower, Podere Montecucco Garden, Umbria, Italy. June.

Paul Harcourt Davies / Blackberry bush (Rubus fruticosus) in flower, Umbria, Italy. June.

Paul Harcourt Davies / Lemon (Citrus limon) flower, Umbria, Italy. June.

Paul Harcourt Davies / St Bruno's lily (Anthericum liliastrum) in flower, Umbria, italy. May.

Paul Harcourt Davies / Tragopogon x mirabilis, a natural hybrid between Goat's beard (Tragopogon pratensis) and Salsify (Tragopogon porrifolius) found in several colour forms, Umbria, Italy. May.

Paul Harcourt Davies / Close up of Goat's beard (Tragopogon pratensis) flower, Umbria, Italy. May.

Paul Harcourt Davies / Common dogwood (Cornus sanguinea) flower head, Umbria, Italy. May.

Paul Harcourt Davies / Mediteranean medlar tree (Crataegus azarolus) flowers, Umbria, Italy. May.

Paul Harcourt Davies / Silvery crocus (Crocus biflorus) in flower growing on path, Tuscany, Italy. January.

Paul Harcourt Davies / Alpine crocus (Colchicum alpinum), an autumn crocus, in flower, Lazio, Italy. August.

Paul Harcourt Davies / Yellow water-lily (Nuphar lutea) in flower, Umbria, Italy. May.

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

Will Watson / Blackthorn or sloe (Prunus spinosa) blossom in hedgerow, Herefordshire, England, UK.

Nigel Cattlin / Lenten rose (Helleborus hybridus) red flower of an ornamental garden plant showing typical structure of flowering Ranunculaceae, Berkshire, UK, February.

Bruce Thomson / Mountain devil (Lambertia formosa) flowering in Eucalypt (Myrtaceae) forest understorey, New South Wales, Australia.

Edwin Giesbers / North African knapweed / Lesser star thistle (Centaurea diluta) Tenerife, Canary Islands

Edwin Giesbers / North African knapweed / Lesser star thistle (Centaurea diluta) close up of stamens on central disc, Tenerife, Canary Islands

John Cancalosi / Cactus bee (Diadasia rinconis) collecting nectar and pollen on Prickly pear (Opuntia sp.) blossom, Sonoran Desert, Arizona, UK.

Robert Thompson / Alstroemeria Lily, close up of stamens. Studio image.

Robert Thompson / Tulip (Tuplia species) close up of anthers, Banbridge, County Down, Northern Ireland.

Robert Thompson / Tulip (Tuplia species) close up of stigma and anthers, Banbridge, County Down, Northern Ireland.

Robert Thompson / Herb-robert (Geranium robertianum) close up of anthers and stigma, Clare Glen, Northern Ireland.