4. Oleander
Oleander is also known as Nerium. It is a rounded shrub or small tree with long, dark green leaves. Nerium comes in a variety of colors. every part of the plant is highly poisonous. The oleander plant contains cardiac glycosides. It is the compounds that can cause acute cardiac toxicity and digestive issues. This plant is mostly used as a decoration for gardens and parks. Oleander chemical substances are widely used in medicine to heal heart disease.