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

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

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

Florian Möllers / Birthwort (Aristolochia clematitis) flowers and leaves, Berlin, Germany, June

Wild Wonders of Europe / Radisics / Close-up of Birthwort (Aristolochia clematitis) flower, Lake Skadar National Park, Montenegro, May 2008

Adrian Davies / Birthwort {Aristolochia clematitis} Crete, Greece

Philippe Clement / Birthwort {Aristolochia clematitis} with flies on flowers, Belgium

Pascal Tordeux / Birthworts / Pipevines / Dutchman's Pipes (Aristolochia clematitis). French Alps, July.

Guy Edwardes / Southern festoon butterfly (Zerynthia polyxena), newly emerged adult, resting on Birthwort (Aristolochia clematitis) stem, near Bratsigovo, Bulgaria. May.

Guy Edwardes / Southern festoon butterfly (Zerynthia polyxena) newly emerged adult, resting on its food plant, Birthwort (Aristolochia clematitis), near Bratsigovo, Bulgaria. May.

Guy Edwardes / Five Southern festoon butterfly (Zerynthia polyxena) eggs laid on Birthwort (Aristolochia clematitis) leaf, near Bratsigovo, Bulgaria. May.

Guy Edwardes / Southern festoon butterfly (Zerynthia polyxena), newly emerged adult, resting on Birthwort (Aristolochia clematitis), near Bratsigovo, Bulgaria. May.