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The following article was written by Leigh Kemp. If you missed his other articles be sure to read them here.
As a young boy growing up on a farm in the Kei River Valley in the Eastern Cape I was fascinated by nature, and stories of nature. The plants and animals of the area were explained to me through the stories of the Xhosa people, and from the vast library my mom had put together over many years. I was also able to observe many of these natural wonders that I learnt about first hand.
One of the stories that stayed with me is of the tree that grew on other trees that needed support to strengthen them, or if not in a state to continue growing then to grow a stronger tree from the demise of the old tree. I was told that the seed of the support tree would be deposited on a branch of the tree that needed support – either by a bird or a monkey – and the seed would sprout and spread to the ground. The roots would then grow into stems to support the ailing tree.
Roots from the sky
If the old tree was too weak to continue then the new roots would simply embrace it into making way for the new tree to grow strong. The new tree provided shelter in the hollow-out section where the old tree trunk used to be and also food through the fruits that were produced. This was the way nature interacted.
I knew the tree as the ‘saving tree’ but later learned that it was one of the strangler fig species [Ficus sp.]. These trees grew in very artistic shapes, embracing rocks and uneven terrain, growing what often seems like many stems – which I also later found out were all roots from one seed.
The figs from my youth were the common wild fig [Ficus burkei] and the forest fig [Ficus craterostoma]. Both these species are from the group known as strangler figs. The strangler figs do indeed grow from a seed deposit through faecal droppings on a branch or in a crevice of a host tree. The seed sprouts roots which grow downwards, eventually taking root in the ground. The roots thicken and even intertwine and as they grow larger they begin to constrict the host tree which more often than not dies and rots away. This explains why many of the large fig trees have hollowed out trunks.
Roots strangling host
There are examples where the host tree survives and forms a symbiotic relationship with the fig. It must be noted though that not all strangler figs grow in this way. There are some that will grow from a seed that falls directly on the ground – or on rocks!
The seemingly multi-stemmed figs are actually meshed roots from the original seed. The roots were shaped by the barriers they grew over on or near the host tree, be it a large branch or even a rock.
The Strangler fig is often thought to be one species but in fact there are number of ficus species that use the ‘strangler’ method of growing.
The legendary banyan trees of India are ficus species of the strangler variety. The Great Banyan Tree in the Acharya Jagadish Chandra Bose Botanical Garden near Kolkata covers nearly 14,500 square meters, making it the widest tree in the world. When seen from a distance it would seem that the tree is a forest, but what appear to be individual trees are actually aerial roots of one tree, over 3500 of them.
THE ROCK-SPLITTING TREE
I have been asked on more than one occasion: ‘There is a tree growing out of the rock. How did it get there?’ I always take time to answer this question as it is the story of the Ficus genus. The question normally comes when we come across one of the rock fig species or even a strangler fig where the seed has fallen in a crevasse of the rock.
Fig growing on rock
These trees could be a ficus of any number of species that has been deposited in a crevasse and has sent out roots that take hold in the ground. It gives the impression that it is the tree that has split the rock.
SPECIES SPECIFIC INTERACTION
The ficus family is renowned for its intricate shapes and angles of growth but there is another side to the genus that is just as fascinating.
Fig root art
All figs are pollinated by tiny wasps, the largest wasp species being 2mm. The wasps are attracted by scent and enter the fruit. A fig fruit is a flowerhead that has turned in on itself, meaning the flowers are sealed up inside the casing. The female wasps enter through a small opening, the ostiole, and lay eggs in the flowers, pollinating at the same time.
The wasp larvae feed on the developing seeds and the fully developed wasps then mate inside the fig. Only the females will leave the fruit after the wingless males have opened a hole in the wall of the fig. The whole process then starts over again.
The fig ripens and is eaten by birds, bats and primates – and also eaten by animals that pick up the fallen fruit from the ground. The seeds are dispersed through the droppings of the various feeding species.
Wild fig fruit
A fascinating fact about the wasps and fig association: each fig species has a species specific wasp associated with it, which means that the fig species will not survive without its specific wasp species. A particular tree will continue to grow but it will never propagate without its species specific wasp.
There is a species of fig in Kirstenbosch Botanical Gardens, Ficus craterostoma, where no species specific wasp occurs for the trees so the flowers remain un-pollinated and no seeds or ripe fruits are produced. There are many places around the world where fig trees were introduced without the species specific wasp – and these trees have not propagated.
Studies are been done on the adaptations of wasps to hybridised fig species – and in some cases the wasps have adapted to the hybridisation.
THE USES OF THE FICUS
Aside from the nutritional value of the fruits figs are used for curing ailments ranging from tuberculosis to stomach cramps. The wood of most fig species is soft and not ideal for furniture but in parts of Africa it is used in the making of cow-hide drums and some of the caskets for mummies of ancient Egypt were made from fig wood, in particular the famous sycamore fig.
One of the better known fig species from history is the aforementioned sycamore, [Ficus sycomorus]. It is mentioned numerous times in the bible and was the tree that Zacchaeus climbed in order to get a better view of Jesus in Jericho.
The Kikuyu in East Africa revere the tree as sacred and all sacrifices to the great creator are performed under a sycamore tree.
About the author: Leigh Kemp grew up in nature on a remote farm in the Eastern Cape. This geared him to a life of travelling the wild places of Africa for more than 35 years as a wilderness guide, tour guide, travel writer and conservationist – learning and collecting information and images on all aspects of the African wilderness. Visit his site here, contact him directly on kempleigh06[at]gmail.com or call him on +27 79 596 6671.