ABOVE: A dwarf , cultivated variety of Ficus microcarpa known as Green Island with small round thick leaves for sale in Kota Kinabalu. Many different varieties of Ficus microcarpa grown as bonsai are popular throughout the world. F. microcarpa bonsai are especially popular in Taiwan where Ficus microcarpa grows naturally in the wild. These bonsai varieties are often exported from Taiwan and sold in urban markets and garden centers in Borneo under a large number of different names.
In Europe the most important commercial cultivation of bonsai is carried out in the Netherlands.
The mistake probably originated with this illustration of Ficus microcarpa (labelled as Ficus retusa) growing in Java, copied from the Atlas der Baumarten von Java published in 1918 by Kooders and Valeton. The Dutch are not only famous as botanists in SE Asia, they are also some of the worlds most skilled horticulturalists. Thus when Dutch horticulturalists turned their skills to bonsai growing it was an understandable error to name their Ficus microcarpa bonsai as Ficus retusa. Koorders et Valeton (1918) Fig Trees of Java