(No.6, Vol.3, July 2013 Vietnam Heritage Magazine)

Flame lily.

Twisted cord flower

Each species that wants to survive has to develop weapons against predators. This article reveals some plants which are toxic and dangerous to humans.

1. Cây Lá ngón (Gelsemium elegans), nicknamed ‘heartbreak grass,’ is well-known among hill tribes as an effective means for suicide. When rain starts falling at the altitude between 200m to 2,000m in Vietnam’s forests, clusters and clusters of yellow Gelsemium elegans begin to bloom brightly. Each light blow of wind caresses those green leaves beautifully, but if there’s a chance that a leaf or a flower from the heartbreak grass could enter a warm-blooded being’s body, then all of its toxicity will immediately go into effect-its alkaloids will cause symptoms of thirst, sore throat, dizziness and nausea, then muscular fatigue, low body temperature, hypotension, teeth clenching, foaming saliva, stomach ache, weak heartbeat and mydriasis and finally a quick death due to apnea. The toxic of Gelsemium elegans descends from the root to the leaves, flowers, fruits and the stem. Since this is a plant with beautiful stunning flowers, we often want to take pictures of it without knowing that it is fatal if we accidentally take a leaf or break a stem from the plant. Its toxic will stick on our hands or feet and eventually will get into our body through open sores or our mouth when we eat.

2. Cây S?n or wax tree (Rhus succedanea L.) The wax tree is popular in Vietnam and is planted mainly in the region of Thanh Son, Phu Tho Province, Northern Vietnam where it is harvested for its resin. People use its resin to make lacquer for woodenware making and lacquer painting. The laccol in the resin can cause severe allergic reactions. Smelling the resin or burning the wood of the wax tree can sometimes ulcerate human skin. Scientists haven’t identified which people will be affect by the resin and which won’t. When infected, the face will swell with red pimples and a heavy, burning and unpleasant feeling.

3. Cây Sui or bark cloth tree (Antiaris toxicaria Lesch.) provides poison for hunting. It is the most horrendous poisonous tree in Vietnam. It often grows in mountainous areas. Its body contains a lot of toxic resin. From ancient times, ethnic minorities in the mountains have used this resin to poison arrows, just one of which can bring down a bull. If the resin gets into our eyes, it will cause inflammation and blindness. If it enters open sores, we will immediately be poisoned; the cardiac muscle stretches, the heart rate will slow down and finally stop. However, it is interesting that it is harmless to people who eat the animals which died from being shot with these toxic arrows. Antiaris provides good bark for making clothes and blankets.

4. Cây Ngót ngh?o or flame lily (Gloriosa superba L.) is the ‘admire-only’ queen of mangrove forests. Found in high mountains and in coastal mangrove forests in Vietnam from Hue in Central Vietnam to Ca Mau Province in the southern tip, the flame lily is a toxic plant with glorious flowers. Gloriosa superba is a long-lived species with a vine body about 1-2m long. Its leaves are long and sharp. Its fruit is a loculicidal capsule with many seeds which turns red when ripe. Flame lily blossoms in May and June and its fruits become mature from June to August. The toxins colchicine, superbine and glucosine are in all parts of the plant. Colchicine is the most vital toxin of the flame lily; a ratio of 5mg of colchicine to 1kg of weight will kill rapidly.

5. Cây s?ng trâu or twisted cord flower (Strophanthus caudatus) almost all species in the family of Apocynaceae, of which Strophanthus caudatus is a member, are toxic. Strophanthus caudatus has beautiful flowers and special fruits which look like bull horns. Resin from this plant is poisonous and is usually mixed with the resin of Antiaris toxicaria to poison hunting arrows. The seeds are the ingredients to make strophanthin, a glycoside used to treat heart failure.

6. Cây b?ng b?ng or giant milkweed (Calotropis gigantea (L.) W.T. Aiton) is a toxic plant living right next to most of us. Many of us might have taken pictures of the giant milkweed with big beautiful flowers, which grows a lot on roadsides of coastal provinces in Central Vietnam. The resin from this plant is used to make medicine. A low dose would be an emetic, but a high dose causes fever, rash and for a person with poor health, it could cause heart pressure, lethargy and difficulty breathing.
The medicine is commonly used to treat mild dysentery, arthritis, scabies, sore, gonorrhoea and syphilis.
*Phung My Trung is a freelance researcher in biodiversity

Wax tree

Heartbreak grass

Giant milkweed

Bark cloth tree



Text and photos by Phung My Trung *