Their differences are: Pu Shu skin is grayish brown, rough and undivided, and the branchlets are densely pilose. Elm bark is gray or dark gray, young bark is smooth, old bark is rough, and bark cracks into long longitudinal cracks. But the bark of beech trees is very thick and that of elm trees is very thin.

Elm (scientific name: elm): also known as spring elm and white elm. , commonly known as "elm pimple", is a deciduous tree of Ulmus, with smooth bark of young trees, grayish brown or light gray, dark gray bark of big trees, irregular deep longitudinal cracks and rough epidermis; Branchlets glabrous or hairy, without swollen cork layer and raised cork wings; Winter buds are nearly spherical or ovoid. Leaves are oval, oval, etc. The leaves are smooth and hairless, the back of the leaves is pubescent when they are young, then they become hairless or some veins have tufted hairs, and the petiole surface is pubescent. The leaves of flowers bloom first and cluster in the axils of branches. Samara sparsely obovate, rounded. The flowering and fruiting period is from March to June (later in Northeast China).

Park (à) tree, alias Pockmarked Park, Pockmarked Park and Shapu, Latin scientific name: Pu Shu. Deciduous trees of Urtica; Distributed in Henan, Shandong, the middle and lower reaches of the Yangtze River, southern provinces and Taiwan Province Province; Vietnam and Laos also have it. Root bark is used as a medicine to treat low back pain and lacquer sore.