Ficus glaberrima photographed by Eka Siswyati at Tapanuli in N Sumatra.
Note that Ficus glaberrima does NOT occur in Borneo and the Malay Peninsular and has a very strange relict distribution. This starts in N. India and runs all the way east to Java across Wallace’s Line to Sumbawa in Eastern Indonesia. See the map at the bottom of this article.
The closest relative is Ficus lawesii which a common fig in New Guinea but an uncommon to rare fig in Borneo. The figs of both species are relatively small and ripen green on distinctive stalks (peduncles), at canopy level. Both attributes indicate dispersal by nomadic fruit bats such as Flying Foxes. See this example of a Ficus lawesii leaf from Sarawak which could easily pass for Ficus glaberrima.