Ficus forstenii fruiting next to the Maliau Basin Study Center in south central Sabah.
It is very common to find the fallen fig leaves of sterile (non fruiting figs) growing high in the canopy. With experience most Section Conosycea stranglers can be distinguished by their leaves alone. Ficus forstenii and Ficus annulata have very similar large leaves with sunken side veins on the upper surface, but they are not difficult to distinguish. See below.
Ficus pisocarpa, Ficus kochummeniana and Ficus annulata are the only other Section Conosycea figs with sunken side veins on the upper surface of the leaf but F. pisocarpa and Ficus kochummeniana always have LESS than 10 pairs of side veins. F. annulata and F. forstenii always have MORE than 10 pairs of side veins.