Oozing out of the ground like a volcanic eruption is a fabulous, bizarre and unique tree. Except it’s not a tree, it’s really more a herb due to its herbaceous ancestors. It can grow up to 18 meters tall and have a huge umbrella shaped canopy, but its branches are spongy and easily broken. Welcome to the Bella Sombra tree Phytolacca dioica.

If you’re looking for unique plants on St Helena Island, then you’ll spot these ones easily. I’m going to come right out and make the boldest claim I can – I think St Helena has oldest Bella Sombra trees in Australia and I think we might also have the most per acre. I told you it was a bold claim, but I’m putting it out there so others can refute it. Except I’m sure I’m right.

The name ‘Bella Sombra’ means ‘Beautiful Shade’ in Spanish, and it is is also known as the ‘Ombu’ in its native place of South America, where it grow on the pampas (lowlands) of Argentina. So why is it now in Moreton Bay, Queensland, Australia? The Bella Sombre trees growing on St Helena were definitely brought across for their ability to create shade in hot exposed areas, as were the Jacarandas and Poinciana trees growing nearby in the Superintendent’s Garden. But, being an ornamental garden, which was created as an impressive, colourful destination for the benefit of important visitors, the shape and unusual growth of these plants would also be a unique addition to the garden.

Lauren and Jenise strolling through the Superintendent’s Garden with the Poinciana tree is full bloom.

The largest Bella Sombra in the Superintendent’s Garden is 15 metres high and completely hollow in the centre (Lauren tells me she’s lost a few kids in there and feared they wouldn’t make it back out!) It also has a distinctive, large, fleshy base that is used to store water – in fact the trunk and branches contain up to 80% water! As the trunk grows and expands, it envelopes everything in its path, engulfing it slowly, lava-style. This one has swallowed up a fence post and part of the wire from the fence some time ago. And the fleshy base just keeps getting bigger.

I don’t know the exact age of this tree, but as the gardens were planted in the 1870’s that makes it around 140 years old. Surrounding it are other Bella Sombre trees that look slightly younger that have probably propagated from the largest one. Yet more are scattered around the island, including this one drawn by Paula Peeters during our recent excursion to the island which stands near the Sugar Mill well. Bella Sombre plants can propagate from either seed or by root suckers that produce several trunks directly from the base. This accounts for their very distinct look as seen below:

There have been more of the trees on the island, but they do tend to drop branches easily during storms as they are so porous and open to rot and some of them are now gone. Apparently the sap is poisonous to animals, though I’d swear no-one told the St Helena cattle while they were there as they seem to have chewed the base of the tree in Paula’s picture right up to cattle reaching height. They have certainly been a favourite tree for the cattle to rest under, and the many, many wallabies on the island. On a hot day with a class of sweating children taking a tour of the island, they are a welcome relief for some time out of the sun courtesy of the ‘beautiful shade.’

In all my time travelling around this beautiful country called Australia, I’ve never come across this tree again. I’d love to know whether these plants were brought out and planted more widely on farms or in ornamental gardens in the colonial times. Or were they just a whim of Superintendent John McDonald in his quest to create a garden selected carefully from every corner of the world?

Give me a shout out if there’s one growing in your place. I’d love to hear from you.

St Helena on the ‘Gardening Australia’ program

And finally, apologies for the announcement that Gardening Australia was showing the St Helena segment on 3rd August. It didn’t happen, so I’ve gone back to my (unreliable) source to find out when it’s on. Sorry! I’ll let you know, as it will be lovely to see which plants are featured.