A torch in the rain forest: thermogenesis of the Titan arum (Amorphophallus titanum)

An outstanding flagship species in the plant kingdom is the Titan arum (Amorphophallus titanum), which produces a fountain-like bloom up to 3 m high. The unique appearance of three simultaneous inflorescences in May 2006 was a chance to analyse the flowering behaviour and thermogenesis of this giant. For the first time, the heating of the central column (spadix) could be documented using a high-performance thermographic camera. Time series analyses of the infrared image sequences revealed that the 3-m high spadix surface heats up in pulses emanating from the base of the inflorescence. The surface temperature reaches over 36 degrees C, compared to the ambient temperature of 27 degrees C. Waves of the carrion-like odour are synchronised with these heat pulses. The combination of heat pulses, the fountainlike shape plus the enormous size lead to a unique type of 'convection flower'. On the basis of our observations, we assume that Amorphophallus titanum is able to overcome thermodynamic decoupling by a self-produced convective process.