On the 20th of July 2016 I attended a book launch at the Pretoria Botanical Gardens. The book is called Guide to Trees Introduced to South Africa by High Glen and Braam van Wyk.
Hugh Glen gave a most informative talk looking back in history to when and where plants were introduced to South Africa covering the Oaks brought in by Jan van Riebeek to the Camphor Trees at Vergelegen and the 140 year old trees in the Durban Botanic Gardens. He also highlighted the importance and various uses that exotic plants have. His talk was followed by co-author Braam van Wyk who gave more detail into the book itself and how the tools are used to help the user identify a specific tree.
The word “Indigenous” has always been debatable and the talk highlighted this by suggesting the following concept: If ‘indigenous’ means locally found in a given area and ‘alien’ means introduced to a given area, then is it accurate to say that a Fever Tree (locally found in Kwa Zulu Natal) planted in the Pretoria area is an alien? The difficulty comes with the term “In a given area” as this could be geographical or political and is a very vague guideline. As a solution Braam van Wyk suggested that we choose Earth as the “given area” and can happily say that all trees are indigenous to Earth and that Aliens can be found on another planet.
I was particularly impressed to hear that the counterpart to this book – Fieldguide to Trees of Southern Africa – has an e-book available. A useful feature is that you can specify your location on a map which then only lists the trees that are local to that area to aid in tree identification.
Another very interesting element to the talk was realising how special South Africa is with the high diversity we have in tree species. I did not know that Finland has only 20 native trees, Spain 25, Great Britain and Ireland combined a mere 38 and France 62. It is amazing to think that Europe and the U.K. combined has 124 species compared to South Africa’s more than 1600 native species. Southern Africa has more than 2100 native species and more than 2000 alien species. Remarkably, Madagascar has an incredibly high biodiversity with 4300 native trees. (Note to self – visit Madagascar!)
I used a few spare minutes to have a quick walk around the Pretoria Botanical Gardens which besides the fact that it is winter and very DRY (actually throughout the country), is looking really beautiful. Here are some plants that are flowering: