Although a number of medicines are derived from plants native to rainforests, there are also a number of plants in the tropics that can cause great harm. While many plants are hazardous only if ingested, other plants can be dangerous if touched. And, while most of these plants are dangerous only to those unlucky enough to be allergic to them, some do not discriminate.
Native to Australia, the lawyer vine, also known as the "wait-a-while," has barbed spines that can embed themselves in skin if touched. If stung, remove the barbs in the opposite direction in which they entered.
Black nightshade is a plant native to the rainforest that contains the alkaloid solanidine, which is a neurotoxin. If ingested, it causes trembling and digestive irritation and, in larger quantities, hallucinations.
The source of castor oil, the highly poisonous castor bean plant has a number of chemical uses but also contains the deadly toxin ricin. Throughout the 20th century, ricin was weaponized and used in biological warfare.
Cowhage, a rainforest legume, has a number of traditional medicinal properties, but its pods and flowers can cause blindness if rubbed in the eyes.
The physic nut has a sweet taste, but cause those who ingest it to throw up. If taken in large quantities, its effects can be lethal.
Also known as black-eyed Susan, the bead vine contains bright seeds often used in jewelry. According to The Handbook of Poisonous and Injurious Plants, the toxin in the seed is only released when the seed's casing is punctured, such as when a seed necklace is threaded.
The strychnine tree, native to the tropics of Southeast Asia, contains the poison strychnine. Strychnine causes deadly muscular convulsions and is used as a common rodenticide.
Also known as the thorn apple and the jimson weed, the devil's apple is a poisonous herb found in all parts of the world, including the rainforest. Similar in its effects to nightshade, devil's apples are can cause delirium and hallucinations.
The stinging tree, native to Australia, is covered in a number of prickly hairs that can cause severe stings, some of which can last for months. For those allergic to the tree, stings can be deadly, so they are best avoided entirely.