Jouan Rius / Teddy Bear cholla cactus (Opuntia bigelovii) flowers, Lost Dutchman State Park, Arizona, USA, April 2014.

Jouan Rius / Saguaro cactus (Carnegiea gigantea) buds and flowers in bloom, Lost Dutchman State Park, Arizona, USA, April.

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.

Paul Harcourt Davies / Yellow bird's nest (Monotropa hypopitys) growing in pine needles. This plant is parasitic upon fungi. Forca D'Ancarano, Norcia, Umbria, Italy, June.

Paul Harcourt Davies / Yellow bird's nest / Dutchman's pipe (Monotropa hypopitys) flowers growing in pine needles. Parasitic plant on fungi. Forca D'Ancarano, Norcia, Umbria, Italy, June.

Paul Harcourt Davies / Yellow bird's nest / Dutchman's pipe (Monotropa hypopitys) flower growing in pine needles. This species is parasitic on fungi. Forca D'Ancarano, Norcia, Umbria, Italy. June.

Jim Brandenburg / Dutchman's Breeches (Dicentra cucullaria) flowers, Minnesota

Dong Lei / Dutchman's pipe (Monotropa hypopitys) flowers, Jiuzhaigou National Nature Reserve, Sichuan Province, China, August.

Tim Fitzharris / Saguaro (Carnegiea gigantea) cactii, Superstition Mountains, Lost Dutchman State Park, Arizona

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

Dong Lei / Dutchman's pipe (Monotropa hypopitys) Lijiang Laojunshan National Park, Yunnan, China, July.