Fagus ferrugineaFagus sieboldii Fagus crenata, known as Siebold's beech, or Japanese beech, is a species of deciduous tree in the family Fagaceae.

In north-east Honshū it grows in large stands from sea level up to 1,400 metres (4,600 ft) but in the south-west of its range it is restricted to mountainous areas and occurs in small, isolated populations.

The crown is rounded and the bark is smooth and grey.

The nut has a short thick stalk, 15 millimetres (0.6 in) long.

There are flattened green whiskers at the base of the husk of the nut.