11 June, 2010

Fever tree, umbrella thorn, mimosa, Port Jackson

Edited October 2014 the fever tree has been renamed Vachellia xanthophloea

The umbrella thorn, Acacia tortilis, with its flat top is so much the epitome of Africa that FNB, First National Bank, has used the silhouette for its logo.

We have planted fever-trees, Acacia xanthophloea, in our garden. The Ungardener for its thorns to discourage climbing over the wall. I choose it for that shimmering, luminous, lime green bark. An unlikely, unreal colour, like a mirage. Just briefly while deciduous, long enough to worry the Ungardener, the bark is spectacular. The thorns are long and vicious, to be observed from a respectful reverent and cautious distance, as with the Agave. In fact the thorns are so long and sharp, that they were used as sewing needles by early settlers.

From PlantZafrica The genus name Acacia is derived from the Greek word acantha meaning spine, thorn or prickle and the species name xanthophloea is derived from the Greek words xanthos meaning yellow and phloios meaning bark. Acacia belongs to the pod bearing family Fabaceae. There are 40 species, subspecies and varieties of Acacia represented in South Africa.

Although the trees are indigenous to South Africa, they are out of place in the Western Cape. Coming from the summer rainfall, grassland, up north in Kruger Park, nearer Johannesburg. But the bark and the graceful and delicate tracery of the branches with its fine leaves, makes it a welcome common-or-garden tree.

Called fever trees by early settlers, because they tend to grow near water, and were blamed for malaria (=bad air) before mosquitoes were discovered and given due blame.

Camel thorn, Acacia erioloba, is popular for braai wood (BBQ to you) but the trees come from the northern desert areas. Where they provide shade, and grow SLOWLY. These trees are protected, but sadly, we often see the wood for sale, regardless!

Australian Port Jackson wattle, Acacia saligna, with its masses of fragrant yellow flowers, has been a part of my life, since I was a child. Known for always having a pocket full of tissues, and a running nose from hay-fever (yes! Fever trees!) Truly terrifying swathes of fire hungry trees, smothering all the indigenous vegetation in its reach. If your Acacia doesn’t have thorns, it is an Australian. South Africa has begun to fight back. In earlier, less informed, less thoughtful times, the trees were brought to Cape Town to bind the sand on the Cape Flats. They can be used as fodder for goats, and the bark was used for tanning leather. But now there are lots of small entrepreneurs harvesting the wood for sale – makes good coals. And the scientists have released parasitic wasps for biological control.

An invasive alien, first they take over our rivers and our mountains. Now, adding insult to the injury, they want to claim the botanical Latin name Acacia for the Australian trees, and leave the epitome of Africa with a new name Senegalia Kew . That plant is the source of gum Arabic, used in food.

And the mimosa? Coming from invasive alien, nasty, Port Jackson flowers, it was a culture shock in Switzerland to see branches of mimosa for sale as earliest spring blossom after the winter. (Silver acacia, Acacia dealbata from Australia and Tasmania, blooming from February to April in the Mediterranean) BTW my only cordon bleu is mimosa – finely chopped boiled egg, because it looks like the mimosa flowers. I am more Garden Bleu, where we bought our bird cage/feeder/lantern.

PS This tree has travelled to St Petersburg to Olga's LiveJournal

Pictures and words by Diana of Elephant's Eye


  1. Wow they are some pretty impressive thorns, wouldn’t wana run into that tree!

  2. Dear Diana of EE, Such very lethal thorns but what a wonderful tree and one which, to my shame, I had not come across before now.

    Congratulations on your 200th posting! May there be many more.

  3. It's a shame how some trees and plants brought in from another country for some sort of purpose, can just take over everything. Here, people brought in kudzu vine from another country (I can't remember which one) to feed cattle (at least I think that's the reason tehy brought it in). But it takes over EVERYTHING. You see it covering huge trees from base of trunk, to tip of branches...it blankets the roadside ditches...

    I love your acacia trees, very interesting to see a tree with thorns. My husband's niece named her baby Acacia. Now that I know what acacia means, I think that's a strange name for a baby? lol

  4. Kyna - the word, is pretty. But yes, a strange child's name.

  5. Congratulations on your first-year blog anniversary and 200th post, Diana! Elephant's Eye is a jewel. I always learn something new from your posts! Your native acacia resembles our native honey locust, of which I have many here at Hawk's Haven. They, too, are amazingly thorny (when I was a child, we used to stage swordfights with the thorns) and have that ferny foliage. Honey locusts bear an abundance of large red-brown pods, and got their name because the pods are apparently sweet (as in John the Baptist's "locusts and honey," apparently actually a reference not to eating locusts but carob pods), but I think I won't try to gnaw on one and find out...

  6. beautiful photos of those wicked looking thorns!!! and congrats on your 200th post! you're a delight!

  7. Beautiful images as always! How different it it to visit your garden - warms me just looking. Love the umbrella shapes of Acacia.

    Congrats on your 200th post

    Laura x

  8. OFB - and apparently the 'wild honey' was dates.

  9. Hi Diana,
    Your acacia has lovely fine leaves, but those thorns sure look lethal!
    It sad to see that our wattle is such an environmental problem in your area and in others around the world. It has been quite unloved by many here too as it is so common and has been blamed for allergies. Interestingly, research is letting it off the hook for that at least in most cases http://www.allergy.org.au/content/view/132/1/
    While wattle doesn't belong running wild in other countries, I'm learning to love it as a natural part of our landscape here that provides food for many of our birds and insects.
    I'm not getting in on the argument about botanic names, as I know very little about the subject!

  10. Those thorns are fierce! I can see them being used as sewing needles, easily. Interestingly, there is a mimosa tree that is an invasive weed in our area. It has similar leaves to yours. It is an Albizia, from China, not acacia, and it does not have thorns. It does have beautiful flowers and attracts hummingbirds.

    Congratulations on 200 posts! That is an accomplishment!

  11. Heidi Gippsland - your link is interesting. Didn't know Paterson's Curse is highly allergenic, and that is a huge problem here. Fallow fields covered in shoulder high swathes of pretty flowers - all P's C.

  12. Hi Elephant

    Thanks for the link. Acacia tortilis is high on my list as I've already got it bookmark for a future article on Savanah habitat restoration. It's a major foundational or Mother tree to it's environment. The University of Cairo has been doing much research with regards it's ability to Hydraulically lift and redistribute water to other plants around them which is a lifesavour to wildlife.

    Check out my "Earth's Internet" blog which is more indepth detailed on the mycorrhizal networkings.

    Thanks again



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Photographs are from Diana Studer or Jurg Studer.
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