Ficus microsyce photographed by Eka Siswyati at Tapanuli in N Sumatra.
This fig has not yet been recorded from Borneo but could occur possibly on Pulau Karimata of the coast of SW Borneo. . The distribution is unusual. F. microsyce is found only in the south of the Malay Peninsular including Singapore and adjacent areas of N. Sumatra. See map below.
The structure of the ostiole is also highly unusual. See the drawings below copied from Berg and Corner (2005).