Family: Juglandaceae
Common Name: Hickory

The name of this genus derives from the Greek karya, meaning 'walnut tree'. They are mostly found in North America and Asia and are cultivated for their hard timber and their ornamental value, although some species are also produced for their edible nuts. Caryas are large, deciduous trees with attractive, pinnate leaves which colour yellow, orange or gold in autumn. The tiny male flowers are borne in catkins at the base of the new growth and the female flowers appear in clusters at its tip. The nut is housed in a thick, green, fleshy covering, similar to that of a walnut.

Species

C. aquatica, bitter pecan, zone 7, has lance-shaped leaves, yellow-downy when young, and a reddish brown, egg-shaped, angled nut. It grows to over 20 m (65 ft).

C. cordiformis, bitternut, zone 5, also grows to around 27 m (88 ft). The fruit is generally borne in pairs of threes and contains the bitter kernels; the bright yellow, winter buds are quite distinctive.

C. glabra, pignut, zone 5, is a medium-sized tree which grows to around 15 m (50 ft). The small, ridged nut is enclosed in a thin skin and contains a dry-tasting kernel.

C. illinoinensis, pecan nut, zone 6, is a deciduous tree which grows to around 10 m (33 ft) tall and 6-7 m (20-23 ft) wide. It has yellow-downy winter buds and smooth, oblong, light brown nuts, with a dark stripe. The kernels are edible, with a pleasant, sweet taste. There are numerous cultivars which should be chosen according to climate.

Cultivation

Caryas like an ordinary garden soil. They are fairly slow growers and are not easily transplanted. Propagate from stratified seed, sown in spring, or by root sprouts. The edible varieties are propagated by grafting.

Climate

There are species suited to various climatic zones.