The Phyto-Philes: The Sycomore Fig
Created | Updated Nov 18, 2012
Sycomore Fig
Willem says: 'The Phyto-Philes are for plant lovers of every size and shape, colour and flavour. As with my Colours of Wildlife column, I'll be featuring one species per article, illustrated with sketches, paintings, and/or photos. Over time I hope to be showcasing the amazing diversity of weird and wonderful plants that occur in South Africa, while also from time to time looking at the flora of other countries. While featuring many spectacular species, I'll not be neglecting the smaller, more humble kinds that are nevertheless fascinating in their own right.'
Today’s entry is about the Sycomore Fig, Ficus sycomorus. This is the wild fig or sycomore mentioned several times in the Bible, for instance being the tree in which Zacchaeus climbed in order to see Jesus (Luke 19:4). The species has been cultivated in Israel and Egypt since ancient times. Its figs are not quite as tasty as those of the domestic fig tree, but it is a much more ornamental species, growing larger and becoming a wonderful shade tree. I think they grow bigger over here than they grow in Israel or Egypt, the climate here, especially in the warm northeastern regions of the country, being more favourable. The majority of this species’ range is in sub-Saharan Africa, except for desert and wet rainforests. It also occurs in the Arabian peninsula. Israel is its northernmost limit.
I’ve featured this species in a previous entry, The Ten Biggest Tree Species of South Africa. It comes in at number three on that list. Here it can reach a height of 35 m/115 ft, a crown width of 50 m/150 ft and a trunk diameter of 4 m/13 ft. A specimen of about this size grows not far from my home town of Polokwane, but I’ve not yet seen it. I’ve seen many other very large and impressive ones, though. As I explain in that article, South Africa is not generally blessed with big trees, more than half of the country being desert or semi-desert, and a large part of the rest being treeless grassland or savannah with widely spaced, small trees. Only a fraction of a percent of the country is covered with natural forest. This is not actually a forest species. It grows in savannah regions, most of the time along the banks of rivers. My painting shows a very large specimen that grows in the Kruger National Park. I took the photo in 1997 and painted it (acrylic) in 2002. This tree stands beside a road leading to a lookout point over a man-made lake on, if I’m not mistaken, the Olifants river. The park features many of these man-made reservoirs to hold water year-round for antelopes and other mammals to drink and for hippos and crocodiles to live in. Elsewhere these rivers don’t always flow … a common joke going like this: what do you do when you fall into a South African river? Answer: stand up and dust yourself off.
But while the riverbed itself might be dry, there is usually water remaining under the surface. Sycomore fig trees reach this water by having powerful, deep-penetrating roots, and so remain green along the riverbanks even after many months of drought. They share their powerful roots with many other wild fig species. A small South African fig tree holds the record for the longest recorded tree roots. Growing on a mountainside, its roots can be seen poking through the roof of a cave over 120 m/400 ft deeper down.
The Sycomore fig’s roots are actually quite impressive above the ground. They form flared buttresses on all sides of the trunk, and snake over the ground for long distances around it. You can see this very well in the photo of me standing by a medium-sized specimen growing in the Letaba Camp of the Kruger National Park (photo taken in 1997 when I was 25). These trees are fantastic for attracting birds! Their figs, which they carry year-round, are large, up to 5 cm/2” in diameter, and often carried in profusion. In the wild they are usually infested with insects, making them unattractive to humans, but the birds feasting on them consider these nothing more than little bonus protein packages. Pretty much all fruit-eating birds will be attracted to these trees, from tiny little white-eyes to large fruit eaters like Turacos and Hornbills. Another interesting thing they will attract is fruit bats! These come into the suburbs over here; they’re mostly epauletted fruit bats (which I will try and feature for Colours of Wildlife sometime) which have unusually cute faces for bats. You hear their high pitched, ringing calls in the night. In nature reserves bushbabies, monkeys and baboons also eat the figs; if they drop any, antelopes and warthogs will come and eat them off the ground. Larger mammals like elephants or kudus will be able to browse them off the trees. They will also browse the large leaves. These are very nutritious and will even stimulate cows to produce more milk! In Africa, traditionally people have used the soft wood as the bottom block for making fire by friction. The inner bark is sometimes used for making a rope. The bark and milky latex are used for some medicinal purposes as well. All in all this tree is very valuable to humans and animals.
Sycomore figs, like all figs, use a very unusual reproductive strategy: they have their own species of tiny wasp that live in the fruits! What we call a fruit or fig is actually the structure enclosing the inflorescence, which is folded in upon itself to form a hollow ball; the fig flowers cover the inner surface. There is just a single, tiny opening leading to the outside. A female wasp will squeeze through this opening, typically losing her wings, antennae and even some of her legs because it’s such a tight fit! She will carry some pollen from another fig (we’ll get to how she acquires it in a minute). She will now deliberately pollinate the flowers inside the fig! But she also lays eggs inside the flowers. Only in some of them … the others prevent her by having long, protruding styles; these are the ones the fig saves for its own reproduction. Those with short styles have open canals in them down which the wasp can push her ovipositor and lay her eggs. The fig actually deliberately makes these flowers especially for the wasps! The female dies after laying her eggs, but the flowers she’d laid them in are stimulated into overgrowth, forming a tissue called a gall that is just right for the hatchling wasp larvae to munch on. These grow, pupate and metamorphose into adult wasps inside the galls. The males come out first; they lack eyes or wings and only have tiny legs. They go to the other galls, bite them open and mate with the females inside. Then all the males band together to cut a hole in the wall of the fig. Fresh oxygen streams in, waking up the females. These now collect pollen from the undamaged flowers in the fig, and then fly out through the hole made by the males. From there they seek out other unripe figs to repeat the process of fertilizing the flowers and laying their eggs. The males all die without ever leaving the fig. The fig itself ripens five days after the females wasps have left. The flowers that had been pollinated by the female wasps at the start have now formed seeds; the entire fig is full of these tiny seeds, which will be scattered far and wide in the droppings of the many birds that came to eat the figs. Only a few of the seeds that land themselves in favourable spots will sprout and form new little fig trees.
I don’t yet have any of these trees myself, but they are planted in Polokwane and many other towns in the warmer regions of South Africa. They need very large gardens to give them enough room to expand. The aggressive roots can crack pavements and other structures. They are excellent choices for planting in large parks and of course on farms. Apart from their size they are attractive for the interesting contorted shapes formed by the trunk, branches and buttress roots. The unusual yellowish colour of the bark is also very striking.
The natural way of reproducing by seeds is only feasible in regions where the gall wasps that pollinate these trees live. Outside these areas, such as in Egypt and Israel, the sycomore fig is propagated by means of cuttings. These can be made from small twigs up to big pieces of branch, or truncheons. Truncheons must be cleared of leaves and left in a shady place to dry for five days or so prior to planting. They can then be planted in a hole with sand at the bottom to prevent the truncheon from rotting, and then kept moist but not wet. These trees cannot stand frost; in cold regions specimens can be grown in large pots or containers in hothouses and pruned to keep them neat and compact. Another alternative is making one into a little bonsai tree!
All fig tree species are fascinating. Southern Africa has a great diversity of them, over thirty known species, growing in habitats as different as deserts, rocky mountains and cliffs, sandy beaches, swamps, savannahs, shrubby thickets, and moist forests. They range from scrambling shrubs to regular trees and, in forests, stranglers – trees growing on and over other trees, eventually suffocating them. Worldwide over 800 species are known, the vast majority growing in tropical rainforests, and all of them have very complex ecologies and rich relationships with other animal and plant species. The domestic fig is of course a well-known species, but several other ornamental species are widely planted throughout the world, the Rubber Fig, Ficus elastica, being a notable example.
