Large deciduous tree to 30 m. Leaves 10-25 cm, oblong-lanceolate; margin serrate-dentate with aristate teeth; glabrous above, pubescent beneath, also becoming glabrous. Catkins 12-20 cm, with conspicuous white anthers; male flowers numerous; female few. Fruit 2-3.5 cm, brown, shiny. Cupule green, bearing dense branched spines.