ABOVE; Sterculia macrophylla: What disperses these spectacular fruit ?
In the Tree Flora of Sabah and Sarawak, Vol. 7 (2011) Wilkie and Behaman list 20 species of Sterculia for Sabah and Sarawak indicating a possible 30-35 species for Borneo as a whole. Their spectacular scarlet seed pods mean that Sterculias are hard to miss but because they have little economic value as timber the ecology of Sterculias is little understood. The local hornbills are certainly interested when they see a fruiting Sterculia and they often visit and remove seeds but there appears to be no aril or food attached to the seed.
The seeds are non-toxic and are eaten by humans when they are known as “Java Peanut”. It is possible that Sterculias are dispersed by rodents and crabs at ground level. The spectacular scarlet pods may be a deception strategy to attract innocent young birds to carry them off before dropping them in disgust away from the parent plant.
Tangisang Burung (Birds Crying): In his classic book the Wayside Trees of Malaya Professor E J H Corner lists a number of trees that the local Malay villagers classified as Tangisang Burung. The birds cry because the spectacular appearance of Sterculia fruit promises much but delivers little or nothing in the way of food !
Illustration from the Rijks Herbarium via Plantillustrations.org