hickory

 

any plant of the genus Carya of the family Juglandaceae (walnut family); deciduous nut-bearing trees native to E North America and south to Central America except for a few species found in SE Asia. The pecan (C. illinoinensis) is one of the most important nut trees of the United States. This tree, the tallest of the hickories, is native from S Illinois through the Mississippi valley to central Texas and Mexico. A rich food (containing 70% or more fat), the pecan is the most popular American nut after the peanut and is used as a table delicacy, in ice cream, and for confectionery, especially the traditionally Southern pecan pies and pralines. Cultivated varieties with unusually thin shells, called paper-shelled pecans, have been developed, but wild pecans are also gathered and sold in quantity. Other hickories having edible nuts that are marketed to a lesser extent include the shagbark hickory (C. ovata) of the E United States, the shellbark hickory (C. laciniosa), chiefly of the Midwest and South, and the mockernut, or white, hickory (C. alba or C. tomentosa) of the E United States. The hickory nut of commerce is usually that of the shagbark (the names shagbark and shellbark are often used interchangeably), which has a relatively thin shell. Native Americans made a food of ground hickory nuts. The abundant oil or fat of the nuts was a staple article in the diets of both Native Americans and early colonists. The pignut (C. glabra) has small nuts of variable quality, usually bitter, that have been used as mast for fattening hogs. Many hickories have been so exploited for their valuable wood that they are in danger of extinction. The wood of several species is extremely hard, heavy, strong, and elastic. It is a preferred wood for golf clubs, wheel spokes, and tool handles and wherever strength and resilience are required. Prairie schooners often carried hickory sticks on their westward treks to replace broken wagon parts and ox yokes. The wood, used also for furniture, is prone to decay in moisture. Shagbark hickory is the most valuable for timber. Hickory is classified in the division Magnoliophyta, class Magnoliopsida, order Juglandales, family Juglandaceae.

For other meanings of Hickory please see Hickory (disambiguation).

Hickory
Shagbark Hickory, Carya ovata
Scientific classification
Kingdom: Plantae Division: Magnoliophyta Class: Magnoliopsida Order: Fagales Family: Juglandaceae Genus: Carya Nutt.
Species
See text

Trees in the genus Carya (from Ancient Greek kary "nut") are commonly known as Hickory. The genus includes 17-19 species of deciduous trees with pinnately compound leaves and large nuts. A dozen or so species are native to North America (11–12 in the United States, 1 in Mexico), and 5–6 species from China and Indochina.

Another Asian species, Beaked Hickory, previously listed as Carya sinensis, is now treated in a separate genus Annamocarya, as Annamocarya sinensis.

Hickory flowers are small yellow-green catkins produced in spring. They are anemophilous and self-incompatible. The fruit is a globose or oval nut, 2–5 cm long and 1.5–3 cm diameter, enclosed in a four-valved husk which splits open at maturity. The nut shell is thick and bony in most species, thin in a few, notably C. illinoinensis; it is divided into two halves which split apart when the seed germinates.

Species and classification

In the APG system, genus Carya (and the whole Juglandaceae family) has been recently moved to the Fagales order.

North America

• Carya sect. Carya — typical hickories
  • Carya floridana Scrub Hickory
  • Carya glabra Pignut Hickory
  • Carya myristiciformis Nutmeg Hickory
  • Carya ovalis Red Hickory (treated as a synonym of C. glabra by Flora N. Amer.)
  • Carya ovata Shagbark Hickory
    • Carya ovata var. australis (syn. C. carolinae-septentrionalis) Southern Shagbark Hickory
  • Carya laciniosa Shellbark Hickory
  • Carya pallida Sand Hickory
  • Carya texana Black Hickory
  • Carya tomentosa (syn. C. alba) Mockernut Hickory

• Carya sect. Apocarya — pecans
  • Carya aquatica Water Hickory
  • Carya cordiformis Bitternut Hickory
  • Carya illinoinensis Pecan
  • Carya palmeri Mexican Hickory

Asia

• Carya sect. Sinocarya — asian hickories
  • Carya dabieshanensis Dabie Shan Hickory (may be synonymous with C. cathayensis)
  • Carya cathayensis Chinese Hickory
  • Carya hunanensis Hunan Hickory
  • Carya kweichowensis Guizhou Hickory
  • Carya poilanei Poilane's Hickory
  • Carya tonkinensis Vietnamese Hickory

Hickory is used as a food plant by the larvae of some Lepidoptera species. These include:

• Brown-tail (Euproctis chrysorrhoea)
• the Coleophora case-bearers C. laticornella and C. ostryae.
• Regal moth (Citheronia regalis), whose caterpillars are known as hickory horn-devil
• Walnut Sphinx (Amorpha juglandis)

Another insect that uses the hickory tree as a food source is the hickory leaf stem gall phylloxera (Phylloxera caryaecaulis). Phylloxeridae are related to aphids and have a similarly complex life cycle. Eggs hatch in early spring and the galls quickly form around the developing insects. Phylloxera galls may damage weakened or stressed hickories, but are generally harmless. Deformed leaves and twigs can rain down from the tree in the spring as squirrels break off infected tissue and eat the galls, possibly for the protein content of the phylloxera, or possibly because the galls are fleshy and tasty to the squirrels.

Uses

Hickory wood is extremely tough, yet flexible, and is valued for tool handles, bows (like yew), wheel spokes, carts, drumsticks, golf club shafts (sometimes still called hickory stick, even though made of steel or graphite), walking canes etc. and for punitive use as a switch or rod (like hazel), and especially as a cane-like hickory stick in schools. Baseball bats (also used as substitute paddle or even modified for physical punishment) were formerly made of hickory but are now more commonly made of ash. Hickory is also highly prized for wood-burning stoves, because of its high caloric content. Hickory wood is also a preferred type for smoke curing meats. In the Southern US, hickory is popular for cooking barbecue, as hickory grows abundantly in the region, and adds flavor to the meat. Hickory is sometimes used for hardwood flooring due to its durability and character.

A bark extract from shagbark hickory is also used in an edible syrup that is similar to maple syrup, with a slightly bitter, smoky taste.

The nuts of some species are palatable, while others are bitter and only suitable for animal feed. Shagbark and Shellbark Hickories, along with the Pecan, are regarded by some as the finest nut trees.

When cultivated for their nuts, note that because of their self-incompatibility, clonal (grafted) trees of the same cultivar cannot pollenize each other. Two or more different cultivars must be planted together for successful pollination. Seedlings (grown from hickory nuts) will usually have sufficient genetic variation.

External links

• Carya Large-format diagnostic photos, Morton Arboretum acc. 29-U-10
• Flora of North America: Carya
• Flora of China: Carya
• USDA Agricultural Research Service: Carya
• Edibility of different species' nuts, from a snack food manufacturer
• Comparison of eastern North American hickories at bioimages.vanderbilt.edu
• Comparison of hickory nuts at bioimages.vanderbilt.edupdc:Hickernissbaam

Donate to Wikimedia