While investigating the buttonweeds last week in the park, I came across of a really nice looking patch of groundcover plant. As I had suspected, it was the Asiatic Pennywort (Hydrocotyle sibthorpioides). I already had pictures of this plant in my website. When I enlarged the view of the flower head back home, it looked from that in those pictures taken in the past though the leaves looked similar. After some investigations, it appeared that the real Asiatic Pennywort was the one that I had just seen in the park. The pictures taken in the past was another Hydrocotyle species.

It did not take long for me to solve the mystery --- the old pictures that I had was Brazilian Pennywort (Hydrocotyle leucocephala), a relatively common aquarium plant originated from South America. Besides being located at the same park that I frequented, I had seen it proliferating in another location. Based on my observation, the Brazilian Pennywort was naturalised and may be as common as the Asiatic Pennywort in the wild. It was not listed in the Singapore Flora checklist published in 2009. A 2014 article published by Reuben Lim mentioned that the genus Hydrocotyle was represented by three species in Singapore, namely the exotic Hydrocotyle javanica and Hydrocotyle umbellate, and the native Hydrocotyle sibthorpioides. Brazilian Pennywort was not mentioned. Most likely, Brazilian Pennywort had been mistaken as Asiatic Pennywort all the while, similar to my previous experience.

From the pictures below, it is quite clear that except for the tiny flower heads, both creepers look exactly identical.

Hydrocotyle leucocephala

Hydrocotyle sibthorpioides