One of the most beautiful forest plants today, the lily of the valley is not as smooth as it looks. This plant can be found mainly in cold climates in the northern hemisphere, some varieties are often used as garden plants. Although highly toxic, lily of the valley is also known for its use for herbs. Because it is believed to help strengthen the memory, the plant is said to be strong enough to retain people's common sense. What is certain is that all parts of this plant are very toxic. This plant contains glycosides that interfere with heart function.