It is a deciduous tree growing to 20 m tall with a broad crown. The leaves are alternate, simple, 10–22 cm long and 4.5–8 cm broad, with a toothed margin. The flowers are produced in catkins 4–20 cm long, with the female flowers at the base of the catkin and males on the rest. The fruit is a densely spiny cupule 4–8 cm diameter, containing two or three glossy brown nuts; these are 2–3 cm diameter on wild trees. The scientific name mollissima derives from the softly downy shoots and young leaves.