Oleander, a toxic tree which grows alongside the pavement or in the medians of many big cities, is raising public concern over its harmful effects on pedestrian health.
In central Da Nang City, hundreds of oleander trees, with heights of more than one metre, grow in between streets or as decorative plants on Ton Duc Thang, Nguyen Van Cu, Truong Chinh and Nguyen Tat Thanh streets.

The poisonous trees are also grown next to the playground in Hoa Khanh Nam Ward in Lien Chieu District.

Phan Van Tan, a resident in Hoa Khanh Nam Ward, said that his children usually went there every afternoon, even picking and playing with the flowers.

"We had no idea how toxic they were," he said.

In many ornamental tree shops on Ha Huy Tap, Dien Bien Phu and Phan Dang Luu streets, oleanders are sold for VND100,000 each.

The trees also reportedly grow in coastal Nha Trang City in Khanh Hoa Province.

Oleanders originated in the Mediterranean and have pink flowers. The poison of the trees, found in its resin, may cause swelling for those who touch it and vomiting, headache, bellyache, possible heart malfunction and even death for those who eat it.

PhD Nguyen Thanh Huyen, head of the National Institute of Medicinal Materials' Department of Medicinal Plant Resources, said that extracts from the tree, called oleandrin, were once used for cardiovascular treatment.

"However, it is now used to produce pesticides because its poison is too dangerous," she said.

Director of Da Nang City's Green Trees-Park Co Ltd Dang Duc Thu said oleanders grew massively as they were easily-developed, colourful and had flowers all year round.

Far away

"Most of the trees were planted as street dividers in highways years ago. They are quite far away from residential areas," he said.

He added that this kind of tree had been banned on city streets to ensure the safety of pedestrians. The company would gradually replace the toxic trees with another kind of ornamental one.

PhD Do Huu Thu, head of the Institute of Ecology and Biological Resources' Department of Plant Ecology, said that relevant authorities should keep a close watch on the growing of African tulip trees (Spathodea Campanulata) to avoid any harmful effects.

The statement was made following a local press report that many big cities planned to grow African tulip trees, which were ranked among the 100 most invasive exotic plants causing serious global consequences by the International Union for Conservation of Nature.

The trees' seeds are said to spread easily. In Central Highland Lam Dong Province over the last two years, about 5,400 trees were grown in nine out of the 12 districts and cities of the province. The trees are also seen on 10 streets in Khanh Hoa Province's Nha Trang City.

Da Nang City plans to grow more than 100 of this kind of tree in Hai Chau District in this month.

Company director Thu told Viet Nam News that he didn't think the trees would harm the environment because they only grew on cement pavements in inner cities.

In recent years, red-ear turtles, yellow snails, giant sensitive trees (mimosa pigra) and Japanese climbing fern, have entered Viet Nam causing big economic losses and environmental damage.

VNS