Factsheet N05: Hickories – Carya species
The hickories, Carya species, are closely related to walnuts (both are members of the family Juglandaceae), and like them are usually large deciduous trees which can live to a great age, 4-500 years, which tend to form upright cylindrical crowns when grown in the open. They have alternate pinnate leaves each with 3-17 leaflets. Male flowers are borne in catkins and female flowers in spikes, to be followed by large fruits consisting of a single nut surrounded by a leathery skin (or outer shell) which splits open at maturity. The foliage is aromatic. All species have pronounced taproots which securely anchor the trees if soil conditions allow. Hickories can easily be confused (especially by leaf) with walnuts: differences are that young shoots have non-chambered pith, and the nuts are smooth-shelled.