The suspense is over!

We’d like to thank all the dedicated Moonflower followers who have joined us in the excitement while we waited for this amazing plant to flower.

Glasshouse Supervisor, Alex Summers, was there to witness its opening and describes how it happened:

“In the morning we saw on the livestream that the sepals on the bud had started to part and by lunchtime it became apparent that it was beginning to open much earlier than expected. It started to open fully over the afternoon, reaching full bloom at 5pm.”

There was a jasmine-like scent when it flowered, though it was not as powerful as expected – which is interesting and shows how much more research needs to be done on these rare plants.

The flower began fade almost 12 hours later. The scent also changed to something much less pleasant (Alex has described it as smelling like public toilets!).

Alex continues: “We are so excited that this rare cactus has flowered now – ever since I realised that it was going to flower soon, we’ve all been in suspense! Everyone here at the Garden has been fascinated and I feel so lucky to have been here to experience it.”

We’ve been overwhelmed by the interest our Moonflower has generated!

The live webfeed on our moonflower page has been watched by over 200,000 people all over the world, and late into the night, our YouTube channel gained a cult of livestream watchers who have watched, waited and commented on every bit of movement (or bug that appeared). As the flower begins to fade, they are bidding their farewells and someone has even written a poem for the Moonflower!

The interest and enthusiasm on social media has also been fantastic and we have been thrilled that the story has also been shared widely across the press, with features on BBC Breakfast News, BBC World, BBC 5 Live!, Sky News, the Guardian, the Times, the Daily Mail and many others.

The flower kept us watching and waiting from Tuesday 9 February, when the shoot had reached 20cm – the length at which its parent plant from Bonn Botanic Garden bloomed, so we thought that ours would flower at a similar length. But no!

In the wild the Selenicereus wittii is documented to flower between 25-27cm so we were happy when ours grew closer to these measurements – it eventually reached 28cm in length and was 15cm wide.

Once it was open, CUBG Director, Professor Beverley Glover, who studies plant evolution and development, was keen to gather as much information as she could about the flower for scientific research and understanding. She says:

“Relatively little is known about the Moonflower, so having it here in cultivation enables us to deepen our understanding about it. I took a sample of a couple of tepals which we will look at under the microscope to analyse the cell shape. They’re currently being stored in the fridge before they die fully and we’ll prepare casts from them to enable us to study them.

I’m really interested to know how the expansion of the floral tube takes place and how the stamens and stigma (that’s the male and female reproductive structures) grow to the right length. I’d also love to explore how the plant has developed various features which fit it for pollination by the hawkmoths. This would probably need access to multiple flowers so might be a job for when the plant flowers again next year.”

The Glasshouse team who have spent the last six years growing and nurturing the plant – which needs a good water every day – were also on standby to pollinate it. In the wild, Selenicereus wittii is pollinated by two species of hawkmoth with extremely long proboscises (tongues), needed to reach the nectar, found at the base of the flower’s long shoot. In cultivation, pollination is done using a paintbrush – this is known as ‘selfing’.

Alex explains: “We’re not sure how successful self-pollination will be as it’s likely in the wild this plant is pollinated with pollen from another flower and self incompatibility is common in epiphytic cacti species. However, we were keen to give it a go. As soon as I saw pollen had been produced on the stamens, I took the pollen, using a small paintbrush, and placed it on the stigma. I repeated this a number of times over the next few hours in case the stigma matured after pollen release – early on during the blooming and also late at night as the scent was changing to the more pungent odour.”

We should know within a month if the plant has set seed. We don’t know what our chances of a successful pollination are, but it is always worth trying. We were similarly sceptical about pollinating our Titan arum in 2017, but we now have over 150 baby plants in our nursery glasshouses! On that occasion we were able to use pollen from other Titan arum plants that were flowering in the UK at the same time, unfortunately, as this is the first flowering of Selenicereus wittii in the UK, we don’t have any other local plants to donate pollen this time round, so self-pollination is our only option.

The plant’s name, Selenicereus wittii, is derived from the Greek (Selene), from the Greek moon goddess, and cereus, meaning “candle” in Latin, referring to the nocturnal flowers.

The species name wittii comes from the man who discovered it – Karl Moritz Schumann (1851 – 1904) was born in Germany and worked as a botanist at the Botanical Museum of Berlin. He was the first author to describe the species in 1900 and named it as Cereus wittii. He acquired the plant from Mr. Kaufmann Witt who had collected it on the banks of the Amazon River, near Manaos, Brazil. Witt sent the specimen to Schumann at the Botanical Museum of Berlin.

Moonflowers can also be seen as a symbol of blossoming in dark times, so we think that this flowering during a global pandemic has been very good timing.

The Glasshouse Range is currently closed for refurbishment. When we are able to open safely (with regards to the building work and Covid-19), visitors will be able to come and see the plant, which grows around the Water Chestnut (Pachira aquatica) in the Tropics House.

In 2020, CUBG had to close for 3 months during our busiest time of the year, cancel public events and courses. We have now reopened, but it is with a greatly reduced visitor capacity, the shop remains closed and the café is open for takeaway only.

This has had a big impact on our income, and we would greatly appreciate your support to help us maintain our world-class collections, continue our work supporting plant science and conservation, and to maintain our heritage-listed landscape. Amazing plants like the Moonflower need a brilliant team and a lot of work behind them.

Please consider supporting us by making a donation today. You can do this here.

If you think that you might become a regular visitor, why not join the Friends of CUBG and enjoy free entry as well as a whole heap of other exclusive benefits.

Thank you, we look forward to seeing you in the Garden.