Bibai is the name of a cypress tree. Evergreen tree, up to 30 meters high, with columnar and conical crown. Branches erect or spreading diagonally. The leaves are of two types, the spiny leaves are alternately opposite and covered with white powder. The scale leaves are grown on four-sided branchlets, rhombus-ovate, with sharp or acuminate apex, and concave glands in the middle and lower part of the leaf back. Dioecious, flowering in March. The cones are nearly spherical, mature in October to November, and contain 1 to 2 seeds.

Pencil cypress, also known as North American juniper, belongs to the family Cupressaceae. It is an evergreen tree that can reach a height of 30 meters and has a columnar and conical crown. Tolerant to drought, low humidity, cold and heat, and barrenness, it can grow on a variety of soils. Native to North America.

It is resistant to pruning and has strong shade tolerance. It is better as a hedge than Platycladus arborvitae. The lower branches are not easy to wither. The color does not change to brown or yellow in winter, and it can be planted in the shade on the north side of the building. In ancient my country, it was often planted in temples and mausoleums as tomb path trees or Berlin trees.