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.

Ficus forstenii 10 IMG_0238 - Copy.JPG
Ficus forstenii fresh leaves. Note that  the main vein (mid-rib) , the side (lateral) veins and the tertiary veins are ALL sunken on the upper surface of the leaf, and they are all very prominent on the undersurface of the leaf.
IMG_2429 - Copy.JPG
Ficus annulata fresh leaves. Note that only the side (lateral) veins are sunken. The mid-rib is actually raised or  slightly prominent.
Ficus forstenii.jpg
Underside dried leaf of Ficus forstenii


Ficus bracteata .jpg
Underside dried leaf of Ficus annulata



Drupacea Tenom leaf scan - Copy
Underside  of an unusually large leaf of F.drupacea from Tenom. Note that the leaf is broader with less side veins than either F. annulta or F. forstenii. F. drupacea leaves are always smooth on the upper surface without any sunken veins.