In most cases fallen fig fruit will be quickly covered in fungus and start to break down. This rapid decomposition is due to the high moisture and sugar content of the fig’s syconium wall. The moist sweet, freshy fruit attracts animals, especially bats and birds, who eat and distribute the fruit and it’s seed through their droppings. Once the fruit falls from the tree the flesh begins to rot and the seed has little chance of germinating.
Not all fig species form freshly fruits. Ficus aculeata and coronata will often form thin walled syconium with no flesh and no appealing flavour. Ficus septica, hispida and congesta are also dry and tasteless. This might be a sign that the fruits attract different kinds of animals to eat and distribute them or maybe they are designed to simple fall from the plant and grow once on the ground? All the plants mentioned above do grow terrestrially so maybe that is the case?
Terrestrial aminals may also be involved in spreading the fallen fruit, maybe even ants, ants will often be seen on fallen fruit from nodosa and the like. One thing I have noticed is that seed germination seems to rely on the syconium being broken up to expose the seed to the elements. So seed of fruit that has fallen and not broken apart has little chance of germinating.
The fruit of Ficus triradiata is a little different. It forms what appears to be a fleshy outer wall but is still quite firm and lacking in sugar. When the fruit falls it can go weeks without rotting and finally when all the moisture is lost, becomes a hard woody ‘nut’ like vessel. This makes me wonder if Ficus triradata has evolved to be distributed by ground dwellers? It can grow as a strangler so obviously it’s fruit is being spread by tree dwellers, but it can also grow directly in the ground, making wonder if it the fruit once dry like a nut might also be distributed terrestrially, maybe by rats?
If this is the case, it would mean that the seed of triradiata could happily germinate once the fruit has dried, possibly waiting for an animal to break open the fruit and expose the seed to moisture.
It’s commonly thought that fig seed doesn’t store well. I’m yet to find proof of this, and have seed in storage waiting to test it’s viability after long term storage. One reason the seed may not last might be the fruit’s high sugar content and then possible infection by fungus or bacteria. The seed of fleshy fruit is also hard to separate from the flesh and the difficulty of removing the flesh may cause premature decomposition of the seed. Ficus triradiata’s fruit on the other hand allows the seed to be easily scratched off the inside of the syconium’s firm wall, with no flesh attached to the seed. This may mean that triradiat’s seed can be stored for long periods without deteriorating, maybe sitting as a time capsule awaiting dispersal.