Hickory is a type of tree, comprising the genus Carya (Ancient Greek: κάρυον, káryon, meaning “nut”). The genus includes 17 to 19 species. Five or six species are native to China, Indochina, and India (Assam), as many as 12 are native to the United States, four are found in Mexico, and two to four are from Canada. A number of hickory species are used for products like edible nuts or wood.

Hickories are deciduous trees with pinnately compound leaves and large nuts. Hickory flowers are small, yellow-green catkins produced in spring. They are wind-pollinated and self-incompatible. The fruit is a globose or oval nut, 2–5 cm (0.8–2.0 in) long and 1.5–3 cm (0.6–1.2 in) diameter, enclosed in a four-valved husk, which splits open at maturity. The nut shell is thick and bony in most species, and thin in a few, notably the pecan (C. illinoinensis); it is divided into two halves, which split apart when the seed germinates.

Beaked hickory (Annamocarya sinensis) is a species formerly classified as Carya sinensis, but now adjudged in the monotypic genus Annamocarya. (source)