Beautiful but Toxic: Poisonous Plants found in the forests of India

India is known for the diversity in its flora and fauna. Our jungles are the cradle of biodiversity and are home to numerous plant and animal species. These animal and plant species have evolved traits that help them survive various challenges in the jungle. To avoid predation, some plants have evolved traits, such as toxins, that warn predators they are toxic and can kill them.

Here in this blog, we will talk about some plants found in Indian forests, known for their beauty but toxic.

Rosary Pea (Abrus precatorius)

 

 

The rosary pea is a deciduous tropical climber found in tropical forests or scrublands in tropical Africa, India, China, Southeast Asia, the Philippines, Australia, and the western Pacific. They can be easily recognized by their bright red seeds with a black spot. The whole plant contains abrin, an extremely toxic substance, but the amount of it is very high in the seeds, and consuming even a small amount can be very dangerous and can cause death. Abrin can be destroyed by heating the seeds above 65°C. The bright red-colored seeds, because of their beauty, are used as beads to make a necklace. This necklace is given to children to protect them against disease.

Though the seeds are highly toxic, they have medicinal properties too. They are used as abortifacients, contraceptives, emetics, and irritants. The seeds are also antiperiodic, bitter, aphrodisiac, diaphoretic, emetic, expectorant, and purgative. The root of the plant contains glycyrrhizin, which is 50-60 times sweeter than sugar, but because of toxins, it is not used as an alternative to sugar.

Yellow Oleander (Thevetia peruviana)

 

 

Native to southern Mexico and other regions of South America, this small, tree-like ornamental plant is recognized for its bright yellow, trumpet-shaped flowers. It is now found across tropical areas worldwide, including Australia, Africa, and Asia, especially in India and Sri Lanka. Although it is not native to India, it is commonly seen at the edges of forests, villages, and rural areas. In some forests, where villages have been relocated recently, this plant can still be found inside the forest areas.

All parts of the plant, especially the seeds and milky sap, contain cardiac glycosides such as thevetin, which directly affects the heart. Even a small quantity can cause a fatal heart attack. Minor symptoms include nausea, vomiting, and irregular heartbeat. There are cases of intentional and accidental poisoning from this plant in parts of South Asia. 

The toxicity of the plant is a deterrent to herbivores and makes it survive in the forests and other places. The plant, despite its toxicity, has very limited medicinal or traditional uses. There are false claims on the internet that say taking small amounts of the crude seed or capsules containing the pulverized material is a purported “natural weight loss” supplement. The crushed roots and dry bark are used to make a poultice, which is applied to the skin to treat skin infections.

Glory Lily (Gloriosa superba)

 

 

One of the most spectacular wildflowers of India, the glory lily often finds its way to the household as an ornamental plant from the wild places. Not a true lily, the glory lily is the only member of this genus in the autumn crocus family (Colchicaceae). Glory lilies are a deciduous, summer-growing tuberous plant from tropical and southern Africa and temperate and tropical Asia. It grows naturally in a wide variety of habitats, from forests to thickets to grasslands. Being a member of the family Colchicacae, all parts of the plant are poisonous and contain a high level of toxic alkaloid colchicine. The tuber of the plant contains the highest amount of toxin. If it is ingested in large amounts, it can be fatal to humans and animals. Though it grows naturally in many parts of the world but is considered a noxious weed in some places like Australia and parts of the US. 

Datura (Datura metel / Datura stramonium)

 

 

Datura can be identified easily by its large trumpet-shaped white or purple flowers. The plant belongs to the family Solanaceae. The common names of Datura are thornapple, stinkweed, and angel’s trumpet. The flowers and fruits have religious importance in India and are offered to Lord Shiva. The plant is used in Ayurveda, the traditional medicinal system of India, to treat various human ailments like ulcers, wounds, inflammation, rheumatism, and gout. All parts of the plant contain high levels of the tropane alkaloids atropine, hyoscyamine, and scopolamine. These alkaloids are classified as deliriants, or anticholinergics. The intoxication of Datura causes delirium (sudden onset of acute confusion), hyperthermia, bizarre behavior, and excessive dilation of the pupil with resultant painful intolerance to bright light that can last several days.

Strychnine Tree (Strychnos nux-vomica)

 

 

The Strychnine Tree (Strychnos nux-vomica) is a medium-sized tree distributed in South and Northeast Asia. The plant contains the alkaloid ‘strychnine,’ which is used in traditional medicine systems, and the plant is a commercial source of this alkaloid. It is harvested from the wild for local uses for food, medicine, and sources of materials. It is an important homeopathic medicine known mainly for digestion, constipation, and gastric problems. The toxic alkaloids strychnine and brucine are found in various parts of the tree, especially seeds and bark. The fleshy pulp of the fruit is edible.

Strychnine is one of the most powerful poisons acting on the central nervous system, causing tonic contractions that last from a few seconds to minutes.

Cerbera (Cerbera odollam) 

 

 

Cerbera is a tree that belongs to the family Apocynaceae (a family known for its poisonous plants), commonly known as the suicide tree. The tree is native to India and other parts of South Asia. The tree grows in the coastal salt swamps and in marshy areas. The seeds of this tree are very poisonous, containing the toxin cerberin. This tree is responsible for 50% of the plant poisoning cases and 10% of total poisoning cases in Kerala. It is reported to be used for both suicide and homicide, often due to its highly toxic properties that can lead to fatal outcomes when ingested. 

Indian Aconite (Aconitum ferox)

 

 

Aconitum, or Indian Aconite, is a perennial herb and a member of the family Ranunculaceae. This herb is native to the high-altitude Himalayan regions of India, Nepal, and Bhutan. It is considered one of the most poisonous plants of the Himalayas. It produces clusters of helmet-shaped flowers that range in color from blue to deep violet. The plant thrives in the alpine and subalpine environment, found at elevations between 2100 and 4500 meters.

The plant contains a high amount of the alkaloid ‘pseudoaconitine.’ This substance is a powerful neurotoxin and cardiotoxin. All parts of the plant contain toxicity, especially the root. Ingestion or even skin contact can lead to severe poisoning characterized by neurological symptoms, cardiac arrhythmia, and respiratory failure.

The plant is listed as critically endangered because of habitat loss and overharvesting from the wild.

Conclusion

Like all other organisms, plants have also devised many ways to survive and prevent predation by herbivores; toxicity is one amongst them. Though toxicity causes harm to the other organisms, some toxins are useful in various medical uses, which makes these plants commercially useful, but also, at the same time, this commercial exploitation sends the plants to the brink of extinction, like Indian Aconite. We have to use them sustainably and prevent them from overexploitation and also protect their natural habitat so that they can survive for long.