The main difference between male and female holly trees in North America lies in flowers. The male flower has 3~4 branches, and the pedicel length is about 7~ 14 mm, while the female flower has only 1~2 branches, and the pedicel length is only half that of the male flower. In addition, the corolla of the male flower is about 5 mm in diameter, the petals are oval, and when they open, they are folded back, while the female flower has no stamens, and the ovary degenerates conically. Simply put, by observing the characteristics of flower branches, pedicel length and petal shape, we can easily distinguish the male and female of Ilex North America. For more information, you can consult the gardener or read books about flowers.