Stapelia gigantea. Also called the Carrion Flower. Although it looks like a cactus it is a succulent. From www.bbc.co.uk/dna/h2g2/A23934404.The giant carrion flower is only one of a large variety of carrion flower species, or Stapeliads. It grows in Southern Africa. It has the largest flowers in the group - up to 40 cm (16") in diameter this also makes it the largest flowered succulent plant species in the world. It is very typical of the group in that these flowers emit a foul odour reminiscent of rotting meat, and thereby attract flies and bluebottles. These insects are not eaten - as some people mistakenly assume - but are merely used as pollinators.