Hickory is a common name for composing the genus Carya, which includes 19 species accepted by Plants of the World Online.[
]
Seven species are native to southeast Asia in China, Indochina, and northeastern India (Assam), and twelve are native to North America. A number of hickory species are used for their edible nuts or for their wood.
Etymology
The name "hickory" derives from a Native American word in an Algonquian language (perhaps Powhatan). It is a shortening of pockerchicory, pocohicora, or a similar word, which may be the name for the hickory tree's nut, or may be a plant milk made from such nuts.[ The genus name Carya is , káryon, meaning "nut".
]
Description
Hickories are temperate forest to subtropical forest trees with pinnation compound leaves and large nuts. Most are deciduous, but one species ( C. sinensis, syn. Annamocarya sinensis) in southeast Asia is evergreen.
Hickory are small, yellow-green produced in spring. They are anemophily and self-incompatible. The fruit is a globose or oval nut, long and diameter, enclosed in a four-valved husk, which splits open at maturity. The nut shell is thick and bony in most species, but thin in a few, notably the pecan ( C. illinoinensis); it is divided into two halves, which split apart when the seed germination.
Some fruit are borderline and difficult to categorize. Hickory ( Carya) nuts and walnut ( Juglans) nuts, both in the family Juglandaceae, grow within an outer husk; these fruit are sometimes considered to be or drupaceous nuts, rather than true botanical nuts. "Tryma" is a specialized term for such nut-like drupes.
Taxonomy
Phylogeny
The oldest fossils attributed to Carya are Cretaceous pollen grains from Mexico and New Mexico. Fossil and molecular data suggest the genus Carya may have diversified during the Miocene.
Fossils of early hickory nuts show simpler, thinner shells than modern species with the exception of , suggesting that the trees gradually developed defenses to rodent seed predation. During this time, the genus had a distribution across the Northern Hemisphere, but the Pleistocene Ice Age beginning 2 million years ago obliterated it from Europe.
Subdivision
The genus Carya (not to be confused with Careya in the Lecythidaceae) is in the walnut family, Juglandaceae. In the APG system, this family is included in the order Fagales. Several species are known to hybridize, with around nine accepted, named hybrids.[
]
Asian hickories
Carya sect. Sinocarya
-
Carya dabieshanensis M.C. Liu – Dabie Shan hickory (may be synonymous with C. cathayensis)
-
Carya cathayensis Sarg. – Chinese hickory
-
Carya hunanensis W.C.Cheng & R.H.Chang – Hunan hickory
-
Carya kweichowensis Kuang & A.M.Lu – Guizhou hickory
-
Carya poilanei Leroy – Poilane's hickory
-
Carya sinensis Dode – Beaked hickory
-
Carya tonkinensis Lecomte – Vietnamese hickory
C. sinensis has sometimes been split out in a separate genus as Annamocarya sinensis,[ as genetic data support it being embedded within the other Asian Carya.]
North American hickories
Carya sect. Carya – typical hickories
-
Carya floridana Sarg. – scrub hickory
-
Carya glabra (Mill.) Sweet – pignut hickory, pignut, sweet pignut, coast pignut hickory, smoothbark hickory, swamp hickory, broom hickory
-
Carya laciniosa (Mill.) K.Koch – shellbark hickory, shagbark hickory, bigleaf shagbark hickory, kingnut, big shellbark, bottom shellbark, thick shellbark, western shellbark
-
Carya myristiciformis (F.Michx.) Nutt. – nutmeg hickory, swamp hickory, bitter water hickory
-
Carya ovalis (Wangenh.) Sarg. – red hickory, spicebark hickory, sweet pignut hickory (treated as a variety of C. glabra by Flora N. Amer. and Plants of the World Online
[)
]
-
Carya ovata (Mill.) K.Koch – shagbark hickory
-
C. o. var. ovata – northern shagbark hickory
-
C. o. var. australis – southern shagbark hickory, Carolina hickory (syn. C. carolinae-septentrionalis)
-
Carya pallida (Ashe) Engl. & Graebn. – sand hickory
-
Carya texana Buckley – black hickory
-
Carya tomentosa (Poir.) Nutt. – mockernut hickory (syn. C. alba)
-
extinction Carya washingtonensis Manchester – Miocene of Kittitas County, Washington
Carya sect. Apocarya – pecans
-
Carya aquatica (F.Michx.) Nutt. – bitter pecan or water hickory
-
Carya cordiformis (Wangenh.) K.Koch – bitternut hickory
-
Pecan (Wangenh.) K.Koch – pecan
-
Carya palmeri W.E. Manning – Mexican hickory
Distribution and habitat
Seven species are native to southeast Asia in China, Indochina, and northeastern India (Assam), and twelve are native to North America, of which eleven occur in the United States, four in Mexico (of which one, C. palmeri, endemism there), and five extending into southern Canada.
Ecology
Hickory is used as a food plant by the caterpillar of some Lepidoptera species. These include:
The hickory leaf stem gall phylloxera ( Phylloxera caryaecaulis) also uses the hickory tree as a food source. Phylloxeridae are related to and have a similarly complex life cycle. Eggs hatch in early spring and the 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 break off infected tissue and eat the galls, possibly for the protein content or because the galls are fleshy and tasty to the squirrels. The pecan gall curculio ( Conotrachelus elegans) is a true weevil species also found feeding on galls of the hickory leaf stem gall phylloxera.
The banded hickory borer ( Knulliana cincta) is also found on hickories.
Uses
Nutrition
Dried hickory nuts are 3% water, 18% , 13% protein, and 64% . In a reference amount, dried hickory nuts supply of food energy, and are a rich source (20% or more of the Daily Value, DV) of several B vitamins and , especially manganese at 220% DV.
Culinary
An extract from shagbark hickory bark is used in an edible syrup similar to maple syrup, with a slightly bitter, smoky taste. The Cherokee people would produce a green dye from hickory bark, which they used to dye cloth.
The nuts of some species are palatable, while others are bitter and only suitable for animal feed. Hickory nuts were a significant food source for indigenous peoples of the Eastern Woodlands of North America since the middle Archaic period. They were used by the Cherokee in Kanuchi soup, but more often edible oil would be extracted through crushing the nuts and then either straining or boiling the remains.
When cultivated for their nuts, clonal (grafting) trees of the same cultivar cannot pollinate each other because of their self-incompatibility. Two or more cultivars must be planted together for successful pollination. Seedlings (grown from hickory nuts) will usually have sufficient genetic variation.
Wood
Hickory wood is hard, stiff, dense and shock resistant. There are woods stronger than hickory and woods that are harder, but the combination of strength, toughness, hardness, and stiffness found in hickory wood is not found in any other commercial wood.[Important Trees of Eastern Forests, USDA, 1974] Hickory is therefore used in a number of items requiring these properties, such as tool handles, bows, wheel spokes, assistive cane, Drum stick and wood flooring. were formerly made of hickory, but are now more commonly made of ash tree; however, it is replacing ash as the wood of choice for Scottish shinty sticks. Traditional are made out of hickory, however since the 1970s lacrosse sticks have switched to plastic heads on metal shafts.
Due to its grain structure, hickory is more susceptible to moisture absorption than other species of wood, and is therefore more prone to shrinkage, warping or swelling with changes in humidity.
Hickory is also highly prized for wood-burning stoves and , as its density and high energy content make it an efficient fuel.[ Hickory wood is also a preferred type for smoking cured 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.
]
Gallery
File:Carya nuts.jpg|Comparison of North American Carya nuts
File:Hickory nuts 6060.JPG|Ripe hickory nuts ready to fall
File:2014-11-02 14 36 58 Hickory foliage during autumn along Woosamonsa Road in Hopewell Township, New Jersey.jpg|Autumn foliage
See also
-
Philips, Roger. Trees of North America and Europe. Random House, Inc., New York. , 1979.
External links
