ABOVE: Ficus callosa growing in a cemetery next to the Tuaran river on Tuaran Rubber Estate 40 km north of Kota Kinabalu on the west coast of Sabah.
INTRODUCTION TO THE 5 OREOSYCEA FIG TREES FOUND IN BORNEO
World: 55 spp. Borneo 5 spp. possibly 6.
Borneo hosts 5 (possibly six) species of Section Orosycea fig trees including Borneo’s tallest fig tree Ficus albipila. Only one of the 5 species, Ficus callosa is locally common, the rest are scarce or rare. In addition, Oreosycea figs appear to have been seriously under-recorded by botanists in the past. To botanists these tall trees with pale smooth trunks and large leaves resemble several species of Artocarpus which in themselves are very variable. Both Ficus and Artocarpus produce copious white latex when the bark is damaged. If the tree is not fruiting only very experienced botanists who know exactly what they are looking for can distinguish these trees from the leaves alone.
|F. albipila||Rare||Yellow–red stipitate with stalk|
|F. callosa||Common Sabah||Greenish yellow with long stalk|
|F. magnoliifolia||Very rare||Greenish with a short stalk|
|F. nervosa||Scarce||Yellow- red with stalk|
|F. vasculosa||Scarce||Pale green-yellow-red. Medium stalk|
Relict distributions: All the Borneo species of Section Oreosycea figs have extensive ranges outside Borneo and are generally most common in areas with a distinct dry season. Note that figs that ripen green are normally dispersed by fruit bats.
It appears that all the Bornean Oreosycea ficus species were previously much more common in Borneo than they are now, probably during a period when the Borneo climate was dryer and more seasonal.
How to distinguish Section Oreosycea fig trees
- Tall trees with bare, straight, pale trunks and large buttresses. No hanging (aerial) or strangling roots.
- Field botanists frequently confuse these trees in the forest with mature Artocarpus trees which look similar except that Artocarpus leaves are generally much larger and the branches tend to hang down..
- The trunks of both Artocarpus and Oreosycea figs produce copious white latex when cut. If you manage to collect the fig fruits they are easily distinguished from any other fruits by the presence of an ostiole. If not fruiting, the leaf is the only guide.
- All Oreosycea fig species appear to be shortly deciduous. (showing bare branches for a few days) during dry seasons. Artocarpus are never fully deciduous
- All leaves including herbarium collections show a waxy shine on the upper surface particularly. However this is also true of some species of Artocarpus e.g. the very common Artocarpus nitidus which is a fig mimic.