The first 2 illustrations and text pages are copied from Berg & Corners’ (2005) Flora Malesiana treatment of Ficus. Note the areas of yellow highlighted in the text, which describe the only distinctive differences between the two species.
DISTINGUISHING FICUS CEREICARPA & FICUS FRANCISCI
Illustrations and text copied from Corner (1978) Ficus dammaropsis and the Multibracteate species of Ficus Sect. Sycocarpus.
Corner 1978 FICUS DAMMAROPSIS AND THE MULTIBRACTEATE SPECIES OF FICUS SECT. SYCOCARPUS
Ficus francisci and Ficus cereicarpa are two very similar small trees with large leaves and cauliferous figs endemic to wet forested areas of Borneo.
- The leaves and growth form of Ficus francisci are almost identical to Ficus cereicarpa except that Ficus francisci is c. 20% smaller in all parts.
2. According to Berg (2005) the only key difference between the two species is that F. francisci has NO NODAL GLANDS whilst F.cereicarpa does have NODAL GLANDS. However see this illustration below from Corner (1978).
3. Another distinction between the two species is the number of bracts on the side of the fig fruit. The fig fruits of Ficus cereicarpa are covered with prominent bracts whilst the fig fruits of Ficus francisci are smooth with longitudinal ridges and no bracts on the external surface of the figs. But Berg’s (2005) description also says of of Cereicarpa “(with or without lateral bracts). ”
Thus whilst the two illustrations in Berg (2005) show a clear distinction between the two species the reality is that they illustrate two ends of a spectrum and the appearance of the two species does overlap. This may indicate a hybrid zone in some areas of northern Borneo where the two species overlap.
CONCLUSION
Berg (2005) notes that he has not come across any ficus hybrids during his research but also notes that the recent scientific literature on Ficus indicates that hybrids are of regular occurrence in low numbers especially where the habitat is isolated e.g. on islands or in the increasingly common patches of fragmented forest in Borneo.
Extract from Berg (2005) p. 58
Botanists often try “to force square pegs into round holes” to coincide with their personal concept of what constitutes a particular species. Ficus morphology in Borneo is incredibly variable even within species.
I believe that it is better to recognize that during the process of evolution and speciation there are bound to be many instances where hybrids and intermediates between two species occur, and to highlight and clarify these differences, rather than hiding them.
This does not negate the fact that the vast majority of Ficus species listed in Berg (2005) are valid species and does not negate the existence of clearly recognizable different species as with Ficus cereicarpa and Ficus francisci.
On this website we take a pragmatic approach in distinguishing between F. cereicarpa and F. francisci. If there are lateral bracts on the side of the fig fruit we call it F. cereicarpa. If there are no lateral bracts we call it F. francisci.