ABOVE: Thespesia populnea from Blanco Flora des Filipinas
Two different species of small shrubby seashore trees with yellow hibiscus flowers grow on sandy shores around the coast of Borneo. Thespesia populnea and Hibiscus tiliaceous.
Hibiscus tiliaceous grows on almost every beach whilst Tespesia populnea is relative rare.
Both species produce yellow flowers with a deep crimson center. The yellow petals turn deep pink over 24 hours. These two very similar species can be distinguished as follows;
1. Both plants produce dry capsules filled with tiny seeds. The capsules of Hibiscus tiliaceous split open (dehisce) when ripe whereas the capsules of Hibiscus tiliaceous only split slightly.
2. The veins on the underside of the leaf where they join the petiole (leaf stalk) of Hibiscus tiliaceous have (very variable) ant attracting glands which are absent in Thespesia populnea