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.

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

Wild Wonders of Europe / della Ferrera / Slavonian / Common oak (Quercus robur) and Ash (Fraxinus sp) forest, near Muilovcica village, Lonjsko Polje Nature Park, Sisack-Moslavina county, Slavonia region, Posavina area, Croatia, June 2009

Jose B. Ruiz / Flowering Ash / Manna (Fraxinus ornus) autumn leaves, Alicante, Spain

Simon Colmer / Ash tree (Fraxinus excelsior) bud in winter, UK

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.

Ingo Arndt / Ash tree leaves {Fraxinus excelsior} Germany

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

Chris Mattison / Long-tailed wild ginger (Asarum caudatum) flower, Oregon, USA