The appeal of daffodils lies in their beauty and durability. Their flowers come in a range of colors like yellowand white and have contrasting cups of orange or pink and a variety of shapes and sizes. Planted in a sunny location where the soil drains well, most daffodils will come back year-after-year. Perhaps best of all, deer and rodents leave daffodils alone because they contain a bitter poison called lycorine.Botanically, all daffodils belong to the genus Narcissus. So "daffodil" is simply the common name for a Narcissus. In the South, "jonquil" is often used as a common name. Technically, it should only be used for the species Narcissus jonquilla and its hybrids.