The flower known for being both a poison and for its beauty is the oleander (Nerium oleander). It is often admired for its attractive, fragrant blooms that come in various colors, making it a popular choice in gardens and landscapes. However, all parts of the oleander plant are toxic if ingested, containing compounds that can cause serious health effects. Despite its beauty, caution is advised when handling or planting oleander, especially in households with children or pets, highlighting the dual nature of this striking flower.