Toxic plants are species that contain harmful chemicals, making them dangerous to humans and animals. These plants can cause a range of symptoms, from mild irritation to severe illness or even death. Common examples include poison ivy, oleander, and deadly nightshade. It is essential to recognize these plants to avoid accidental poisoning. Many toxic plants produce compounds as a defense mechanism against herbivores. Some toxins can affect the nervous system, while others may cause digestive issues. Proper identification and knowledge of these plants are crucial for safety, especially for those who enjoy outdoor activities or gardening.