What are the differences between tree peony and herbaceous peony?

Tree peony and herbaceous peony are placed in the same genus, Paeonia, in the family Paeoniaceae. The leaves and flowers are similar, but there are many differences between both sides. Firstly, tree peony is a shrubby plant with a permanent woody branch structure, while herbaceous peony is a perennial herbaceous plant with new growth each year from ground level. Secondly, the florescence of herbaceous peony is 2-3 weeks later than tree peony. Thirdly, the life-span of tree peony is longer than herbaceous peony, while herbaceous peony is better than tree peony in cold-resistance. Fourthly, the flowers of tree peony are general bigger than herbaceous peony.  more