VietNamNet Bridge – Cam cu bon (Hoya bonii) flowers have been discovered in Cat Ba Island of the northern port city of Hai Phong, over 100 years since this species was seen in Vietnam (1884).

Scientist Pham Van The from from the Institute of Ecology and Biological Resources of the Vietnam Academy of Science and Technology found a rare Hoya bonii flower tree during a field survey in May 2016. 

After comparing the flower with specimens preserved in museums and doing research, scientists confirmed that this was the Hoya bonii species, belonging to the family Apocynaceae, which only exists in Vietnam.

This is a vine species, with heart-shaped leaves, thick and hard. The species grows on limestone or clings to trees. They blossom in May, with white flowers and pink center, and have 5 symmetrical wings like stars.

Since the French botanist Costantin described Hoya bonii as a new species in 1912, no specimen had been seen in Vietnam until this May. 

The tree found in Cat Ba.

"Costantin announced the new Hoya bonii species based on specimens collected by R.P Bonn in 1884 in northern Vietnam, which are now preserved at the Museum of Paris," The said.

With this discovery, researchers have identified this rare species distributed on a very narrow area in Cat Ba National Park. They suggested to the park to take measures to protect this rare variety.

Le Ha