Amur corktree (Phellodendron amurense)

Rutaceae, Plants of Illinois. In Willow Springs, on the property of the Forest Preserve District of Cook County at McMahon Preserve. Frequent in shaded wet prairie that was planted by forestry personnel several decades ago, the trees now spontaneous. Here, it grew with Leersia virginica, Polygonum punctatum, Polygonum virginianum, Prunus serotina, and Quercus macrocarpa.