ABOVE: Ficus treubii. A cross section of an almost “ripe” male fig with the fig wasps about to emerge from the gall flowers. Note the magenta stain which rapidly develops on the recently cut surfaces indicating a form of oxidation known as the Schiff process. This likely indicates the presence of an anti-fungal or toxic compound similar to potassium permanganate. This compound is obviously present in male figs but not female figs.
Ficus treubii is dioecious i.e. separate female and male trees. Male fig trees produce male figs which act as brood chambers for fig wasps whilst only female fig trees produce seed figs. Ripe female Ficus treubii female figs are slightly smaller than male figs. The difference in leaf size between the two sexes in the photo above is not thought to be significant. Typically young earth fig trees of most species produce larger leaves than larger older trees.
Male Ficus treubii fig tree growing next to a drain stream behind Mushroom Shed 84 on the Kota Kinabalu to Tambunan road in Sabah. The arrow points to a single ripe male fig. See close up photo below. There is a small colony of both male and female F. treubii fig trees growing along the stream.