Large tree to 25 metres. Buds large, deep brown and sticky. Leaves pinnate with 5 to 7 leaflets, coarse toothed. Flowers white each of the 4 petals with a yellow or pink blotch at the base 9 to 11 mm in large erect conical panicles. Fruit globose up to 6 cm yellowish green when ripe, spiny splitting to reveal 1 or 2 shiny brown seeds (conkers).

Open wooded areas.

May and June.

Deciduous.

Common in Britain though slightly less so in Scotland

Quite common in Leicestershire and Rutland. In the 1979 Flora survey of Leicestershire it was found in 417 of the 617 tetrads.