Hickory

Taxobox
name = Hickory

---

image_width = 230px
image_caption = Hickory at Morton Arboretum
Accession 29-U-10
regnum = Plantae
divisio = Magnoliophyta
classis = Magnoliopsida
ordo = Fagales
familia = Juglandaceae
genus = "Carya"
genus_authority = Nutt.
subdivision_ranks = Species
subdivision = See text

Trees in the genus Carya (from Ancient Greek κάρυον "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 wind-pollinated 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.

Tryma

Some fruits are borderline and difficult to categorize. Hickory nuts (Carya) and Walnuts (Juglans) in the Juglandaceae family grow within an outer husk; these fruits are technically drupes or drupaceous nuts, and thus not true botanical nuts. "Tryma" is a specialized term for such nut-like drupes. [ [http://waynesword.palomar.edu/fruitid1.htm Identification Of Major Fruit Types] ] [ [http://waynesword.palomar.edu/ecoph8.htm Fruits Called Nuts] ]

Uses

Hickory wood is extremely tough, yet flexible, and is valued for tool handles, bows (like yew), wheel spokes, carts, drumsticks, lacrosse stick handles, golf club shafts (sometimes still called "hickory stick", even though made of steel or graphite), the bottom of skis, walking canes etc. and for punitive use as a switch (like hazel), and especially as a cane-like hickory stick in schools. Baseball bats 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 United States, 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 pollinate each other. Two or more cultivars must be planted together for successful pollination. Seedlings (grown from hickory nuts) will usually have sufficient genetic variation.

See also

* walnut (also used in waterskis)

References

External links

* [http://www.cirrusimage.com/hickory.htm "Carya"] Large-format diagnostic photos, Morton Arboretum acc. 29-U-10
* [http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=105766 Flora of North America: "Carya"]
* [http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=105766 Flora of China: "Carya"]
* [http://extension-horticulture.tamu.edu/carya/species/index.htm USDA Agricultural Research Service: "Carya"]
* [http://www.thenutfactory.com/kitchen/edible/facts-hickories.html Edibility of different species' nuts, from a snack food manufacturer]
* [http://www.cas.vanderbilt.edu/bioimages/pages/compare-hickories.htm Comparison of eastern North American hickories at bioimages.vanderbilt.edu]
* [http://www.cas.vanderbilt.edu/bioimages/pages/carya-fruits.htm Comparison of hickory nuts at bioimages.vanderbilt.edu]