By mere chance, I actually grew 2 of this plant in a pot which eventually flowers and produce 2 seeds. I suspected that the seeds of the 2 plants came with the soil that I bought from a nursery. The identity of the plant was eventually revealed when it bear fruits. Below are the development of the 2 plants over time.
[A] The birth of the "unknown" plants in October 2009:
[B] Progressive growth of the 2 plants over the next 2 months:
[C] The plants were moved to a larger pot in January 2010. They adapted quite well to the new home:
[D] Between July and August 2010, they had grown to a small shrub with many leaves:
[E] One year later in September 2010, the flower buds started to appear:
[F] Finally, in March 2011, I got the first and only 2 fruits. This was the time that I eventually confirmed the identity of this "unknown" plant. The plants eventually died though I could not recall when it happened --- likely in the second half of 2011.
In July 2013, someone checked with me on the availability of this plant in Singapore. I then realized that I still had the 2 dried fruits with me, kept in a sealed container. In March 2018, I found a seedling in a small pot that I suspected that it might be another Croton tiglium. I had just set up this pot a month ago to nurture a seedling of the local cherry tree (Muntingia calabura).