When in bloom, titan arum’s flower spike (spadix) produces heat. All that most people know of the tropical tuberous genus of Amorphophallus is the heroically nasty odour of the Sumatran Giant, the titan arum (Amorphophallus titanum). When titan arum bloomed for the second time at Kew in 1926, it attracted such big crowds that the police were called to control them.. Titan arum has the world’s largest unbranched inflorescence (flowering structure) that can reach 3m tall.. The Titan arum at Kew lives behind the scenes at Kew's Tropical Nursery and is sometimes on display in the Princess of Wales Conservatory. In 1889, Titan arum flowered for the first time ever outside its native Sumatra, Indonesia, right here at Kew. Bonn University Botanic Garden in Germany was instrumental in finding the correct conditions needed to make Titan arums reliably flower. Last flowering in 2018, it reached 3 metres tall and it's tuber weighed 118kg.