I will attempt to differentiate two very similar-looking Sterculia tree species, Sterculia oblongata and Sterculia parviflora which I came across in the same park, sometimes planted side by side. The overall appearance, leaves, flowers and fruits of these 2 tall trees were all very similar.

When I first saw a few Sterculia oblongata trees in the recent months, I thought they were Sterculia parviflora and did not too much attention on them. Then, several of the trees started flowering profusely. While snapping pictures of the flowers, I started to pay closer attention to the other features of the tree. As I was confused over the 2 type of trees, it was hard for me to find a “real” Sterculia parviflora to compare. After reading up on more information of the trees online and staring hard at a few more trees in the park as well as the pictures shared online, I kind of figured out their subtle differences which I hope I am correct.

Looking up at the dense leaves on the 2 trees might be hard to differentiate between them. However, the fallen leaves on the ground might provide a better visual and focus to the clues. The first clue was the shape of the leaf base, the part where the leaf stalk attached. Sterculia oblongata has a round to acute leaf base while that of Sterculia parviflora is usually cordate. The second clue was the broader and slightly shorter leaves of Sterculia parviflora compared to a more elongated shaped leaves of Sterculia oblongata. A good resource for comparison would be the dried leaf specimen images from Kew Science website [Sterculia oblongata / Sterculia parviflora]. Besides the feature of the leaves, there might also be differences in their flowers. But, I had yet to get a hold of the close-up pictures of the flowers of Sterculia parviflora to make the comparison.

In the Plant List website, Sterculia oblongata is an unresolved name. The pictures in the Singapore Biodiversity website only showcased the flowers with no other features. The best quality pictures on this plant is available at the Trees of Asia website. NParks had published a pictorial guide on the comparison of 3 Sterculia species but Sterculia oblongata was not one of them. Overall, there appeared to be much less online information on Sterculia oblongata compared to Sterculia parviflora.