The Titan Arum
Peter Boyce and Jenny Evans attempting
self-pollination of Amorphophallus titanum.
The flowering of Amorphophallus titanum at Kew during July 1996 attracted worldwide media attention. The titan arum is often claimed to produce the largest flowering structure and one of the foulest odours. It was the fifth recorded flowering of A. titanum at Kew since a plant, raised from seed collected by the titan arum's discoverer, Italian naturalist Odorado Beccari, flowered here for the first time in Europe on 21 June 1889.
The latest plant, a gift from the Hortus Botanicus, Leiden, was grown firstly in the Lower Nursery by John Norris but was moved to Mike Marsh's team in the Princess of Wales Conservatory where there was sufficient head room for the development of the immense solitary leaf. After a critical period of dry dormancy, the tuberous stem (weighing 30 kg) was replanted late last year and the inflorescence appeared in early July. This grew at an average rate of 10 cm per day, finally attaining a height of 2.05 m when it opened on the evening of 30 July.
The odour of A. titanum pulsed, with peaks occurring at female and male flower receptivity during the first and second evenings of flowering. Dr Geoffrey Kite was able to trap the odour and determine that the major constituents were dimethyl disulphide and dimethyl trisulphide, two compounds with sickening smells. The results were presented later at Kew's Reproductive Biology '96 conference.
While A. titanum undeniably has the bulkiest inflorescence in the Araceae it is not the largest in terms of vertical size. That honour belongs to Amorphophallus gigas which has a similarly sized spathe and spadix carried on a 3-4 m peduncle. Perhaps even more remarkable is the recently described A. pusillus from Vietnam that has an inflorescence just 3 cm tall.
Contact: Peter Boyce (0181-332 5207)