Dead Horse Arum, Helicodiceros muscivorus, in flower. The picture shows the spathe, dull purple, about 10x15cm in size. The bristled spadix ( centre) gives rise to a second common name, the Rat Tailed arum. The base of the spadix bears male and female florets in a hollow chamber (behind the spathe, not visible here). The spadix is thermogenic. As the female florets become receptive, it generates heat to raise the chamber temperature by up to 12篊 above ambient. This promotes dispersal of the putrid odour (the "Dead Horse"), which attracts blowflies. Visiting flies (eg top right) push past downward facing spadix hairs to reach the chamber, becoming trapped overnight. If carrying pollen, they cross-pollinate the female florets as they try to escape. The next day, the male florets shed pollen and the hairs wilt. The flies are set free to carry fresh pollen to the next flower they visit.