Cambridge University Botanic Garden successfully raises 160 young titan arum plants

Cambridge University Botanic Garden (CUBG) has successfully raised 160 ‘baby titans’ from the 2017 flowering of its titan arum Amorphophallus titanum plant ‘Titus’.

This is believed to be the first time such a large number of plants have been successfully raised in cultivation in the UK.

Native to Indonesia, titan arum plants are categorised by the IUCN as an endangered species.

They flower infrequently and when they do, the flower and its pungent smell only last for around two days, as the stench it produces is the plant’s mechanism to lure pollinators in the wild.

Botanic gardens play an important role in maintaining a viable population of this extraordinary species outside its rainforest home in Sumatra, as its seed will not survive being stored.

In cultivation, the plant has to be hand pollinated with pollen from a different individual as the titan arum cannot self-pollinate. Until now, successful pollination of these plants in cultivation is limited to around 20 events.

CUBG used the 2017 flowering of their titan arum to discover more about successfully pollinating the plant by experimenting with two different types of pollen – fresh and frozen – and recorded the results, which they are now sharing with other botanic gardens.

CUBG glasshouse supervisor Alex Summers said: “We’re very excited to announce that we’ve successfully reached the stage of having 160 small titan arum plants.

"This is a result of us experimenting with using different pollen, waiting to see if fruit was set, extracting and sowing seeds fresh from the fruit and then nurturing the seedlings through their first dormancy period – which is the trickiest part of the whole process.”

This whole process has taken almost two years as Titus’ flowered in June 2017.

On the first night of opening, Alex used fresh pollen sent from the Eden Project and frozen pollen from the Royal Botanic Garden Edinburgh to pollinate ‘Titus.’

He said: “We partitioned the flower structure so we knew which pollen came from which source, so when it came to produce its fruits we could record where the pollen came from and whether there would be any difference in success rates from using fresh and frozen pollen.

"What was interesting to discover was that fruit with viable seed failed to set from the frozen pollen but we did get fruit from fresh pollen.

"This process has shown us that freezing pollen probably kills it, and that fresh pollen should be used for fruiting success.”

botanic.cam.ac.uk