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

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The tiny seeds of Thespesia populnea  seeds  are sea dispersed . Photo from Wikimedia Creative commons MHNT.BOT.2009.13.12.jpg

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