Juergen Freund / Timelapse of a Cairns birdwing (Ornithoptera euphorion) butterfly caterpillar metamorphosing into a chrysalis, Queensland, Australia, April.

Juergen Freund / Timelapse of a Cairns birdwing (Ornithoptera euphorion) butterfly caterpillar emerging from egg on an Dutchman's pipe (Aristolochia) leaf and feeding, Queensland, Australia, April.

MYN / Paul Harcourt Davies / Caterpillar larva of Southern festoon butterfly (Zerynthia polyxena cassandra) on foodplant (Aristolochia rotundifolia) Italy, May. meetyourneighbours.net project

Wild Wonders of Europe / della Ferrera / Flowering birtworth (Aristolochia clematitis) by Ash trees (probably Fraxinus angustifolia) in riparian forest along the Trebizat River, Bosnia and Herzegovina, May 2009

Jose B. Ruiz / Birthwort / Dutchman's Pipe (Aristolochia sempervirens), Alcal de Guadara, Seville, Spain

Heather Angel / Brazilian Dutchman's pipe flower (Aristolochia gigantea) with green inflated pouch. Flower smells of carrion to attract fly pollinators. Cultivated in glasshouse, Surrey, England, UK. Native to Br...

Heather Angel / Brazilian Dutchman's pipe flower (Aristolochia gigantea) with green inflated pouch. Flower smells of carrion to attract fly pollinators. Cultivated in glasshouse, Surrey, England, UK. Native to Br...

Eladio Fernandez / Dutchman's pipe (Aristolochia passiflorifolia) Camaguey, Cuba, July.

Mike Read / Andalusian Dutchman's pipe (Aristolochia baetica) Quinta do Lago part of Ria Formosa Nature Reserve, Algarve, Portugal, February.

Paul Harcourt Davies / Birthwort (Aristolochia clematitis) Umbria, Italy, June.

Philippe Clement / Close up of European birthwort (Aristolochia clematitis) in flower, native to Europe, June

Adrian Davies / Birthwort (Aristolochia rotunda), Provence, France, May.