One of the real difficulties that I deal with every day is how to identify a fig in someone’s collection.
Simply put this is frequently a very difficult task. There are many plant characteristics that botanists use to ID a plant. One of the really important characteristics would be the syconia or figs of that plant. The problem is that many of our bonsai figs rarely if ever have syconia.
One factor that is often mentioned is the color of the petiole as a plant identifying feature. In my experience the color of the petiole can vary greatly in seedlings of the same species. In fact the color of the petiole can vary even on the same plant.
In the pictures you can see one plant of Ficus macrophylla. The close ups reveal a normal yellow/green petiole on some of the leaves and a red petiole on other leaves of the same plant. Conclusion is that the leaf petiole color is not a reliable chracteristic to ID your figs.
The definitive reference work on Ficus
for bonsai. The book is a softcover, 8 by 10 inch volume, with 144 color pages, containing detailed information for the beginner as well as the advanced hobbyist.