Tree to 20 m; twigs and petioles at first pilose and sometimes glandular, later glabrescent; lvs narrowly to broadly oblong or ovate, short-acuminate, sharply and often doubly serrate; fruiting catkins short-cylindric, 3–5 cm, each inflated sac flattened-ovoid 1–3 cm, bristly at base; nutlet 5 mm; 2n=16. Moist or dry woods and banks; N.S. to Man., s. to Fla. and Tex.