Ficus microcarpa (Moraceae) is a well known and popular tree species in Hong Kong due to its frequent occurrence near where people lives. It grows and develops quickly and has a broad and dense canopy which makes it particularly good to provide shade. Among the native Ficus species in Hong Kong, it is one of the few species which has small and elliptic leaves with tapering base. Ficus microcarpa is a widespread species in Asia (mainly Eastern and Southern parts) and Australia.
There is another small leaf Ficus species which resembles F. microcarpa quite much, which is Ficus concinna. It is a recent discovery which had probably been overlooked in the past. Only a few individuals have been found so far. Its appearance is like Ficus microcarpa but aerial roots are mostly absent. Also, leaf veins of F. concinna is more conspicuous than that in F. microcarpa (See photographs above). By combing these differences you will probably be able to seperate them in the field! Start checking small-leaf Ficus and see if you could find more F. concinna!