''Carya tomentosa'', (mockernut hickory, mockernut, white hickory, whiteheart hickory, hognut, bullnut) is a tree in the
Juglandaceae
The Juglandaceae are a plant family known as the walnut family. They are trees, or sometimes shrubs, in the order Fagales. Members of this family are native to the Americas, Eurasia, and Southeast Asia.
The nine or ten genera in the family have ...
or walnut family. The most abundant of the
hickories, common in the eastern half of the
US, it is long lived, sometimes reaching the age of 500 years. A straight-growing hickory, a high percentage of its wood is used for products where strength, hardness, and flexibility are needed. The wood makes excellent fuel wood, as well. The leaves turn yellow in Autumn.
The species' name comes from the Latin word ''tomentum'', meaning "covered with dense, short hairs," referring to the underside of the leaves, which help identify the species. Also called the white hickory due to the light color of the wood, the common name mockernut likely refers to the would-be nut eater, who would struggle to crack the thick shell only to find a small, unrewarding nut inside.
Habitat
Native range
Mockernut hickory, a true hickory, grows from Massachusetts and New York west to southern Ontario, and northern Illinois; then to southeastern Iowa, Missouri, and eastern Kansas, south to eastern Texas and east to northern Florida. This species is not present in Michigan, New Hampshire and Vermont as previously mapped by Little.
[Manning, W. E. 1973. The northern limits of the distributions of hickories in New England. Rhodora 75(801):34-35.] Mockernut hickory is most abundant southward through Virginia, North Carolina, and Florida, where it is the most common of the hickories. It is also abundant in the lower Mississippi Valley and grows largest in the lower Ohio River Basin and in Missouri and Arkansas.
[Nelson, Thomas C. 1959. Silvical characteristics of mockernut hickory. USDA Forest Service, Station Paper 105. Southeastern Forest Experiment Station, Asheville, NC. 10 p.][Nelson, Thomas C. 1965. Silvical characteristics of the commercial hickories. USDA Forest Service, Hickory Task Force Report 10. Southeastern Forest Experiment Station, Asheville, NC. 16 p.]
Climate
The climate where mockernut hickory grows is usually humid. Within its range, the mean annual precipitation measures from in the north to in the south. During the growing season (April through September), annual precipitation varies from . About of annual snowfall is common in the northern part of the range, but snow is rare in the southern portion.
Annual temperatures range from 10 to 21 °C (50 to 70 °F). Monthly average temperatures range from 21 to 27 °C (70 to 80 °F) in July and from -7 to 16 °C (20 to 60 °F) in January. Temperature extremes are well above and below . The growing season is about 160 days in the northern part of the range and up to 320 days in the southern part of the range.
[U.S. Department of Agriculture. 1941. Climate and man. U.S. Department of Agriculture, Yearbook of Agriculture. Washington, DC. 1248 p.][U.S. Department of Commerce, Environmental Science Service Administration. 1968. Climatic atlas of the United States. U.S. Department of Commerce, Environmental Data Service, Washington, DC. 80 p.]
Soils and topography
In the north, mockernut hickory is found on drier soils of ridges and hillsides and less frequently on moist woodlands and alluvial bottoms.
The species grows and develops best on deep, fertile soils.
[Halls, Lowell K., ed. 1977. Mockernut history, ''Carya tomentosa''. In Southern fruit producing woody plants used by wildlife. p. 142-143. USDA Forest Service, General Technical Report SO-16. Southern Forest Experiment Station, New Orleans, LA.
] In the Cumberland Mountains and hills of southern Indiana, it grows on dry sites such as south and west slopes or dry ridges. In Alabama and Mississippi, it grows on sandy soils with
shortleaf pine (''Pinus echinata'') and
loblolly pine
''Pinus taeda'', commonly known as loblolly pine, is one of several pines native to the Southeastern United States, from East Texas to Florida, and north to southern New Jersey. The wood industry classifies the species as a southern yellow pine. ...
(''P taeda''). However, most of the merchantable mockernut grows on moderately fertile upland soils.
Mockernut hickory grows primarily on
ultisol
Ultisols, commonly known as red clay soils, are one of twelve soil orders in the United States Department of Agriculture soil taxonomy. The word "Ultisol" is derived from "ultimate", because Ultisols were seen as the ultimate product of continu ...
s occurring on an estimated 65% of its range, including much of the southern to northeastern United States.
[U.S. Department of Agriculture, Soil Conservation Service 1975. Soil taxonomy: a basic system of soil classification for making and interpreting soil surveys. U.S. Department of Agriculture, Agriculture Handbook 436. Washington, DC 754 p.] These soils are low in nutrients and usually moist, but during the warm season, they are dry part of the time. Along the mid-Atlantic and in the southern and western range, mockernut hickory grows on a variety of soils on slopes of 25% or less, including combinations of fine to coarse
loams, clays, and well-drained quartz sands. On slopes steeper than 25%, mockernut often grows on coarse loams.
Mockernut grows on
inceptisol
Inceptisols are a soil order in USDA soil taxonomy. They form quickly through alteration of parent material. They are more developed than Entisols. They have no accumulation of clays, iron oxide, aluminium oxide or organic matter. They have an o ...
s in an estimated 15% of its range. These clayey soils are moderate to high in nutrients and are primarily in the Appalachians on gentle to moderate slopes, where water is available to plants during the growing season. In the northern Appalachians on slopes of 25% or less, mockernut hickory grows on poorly drained loams with a
fragipan. In the central and southern Appalachians on slopes 25% or less, mockernut hickory grows on fine loams. On steeper slopes, it grows on coarse loams.
In the northwestern part of the range, mockernut grows on
mollisol
Mollisol is a soil type which has deep, high organic matter, nutrient-enriched surface soil ( a horizon), typically between 60 and 80 cm in depth. This fertile surface horizon, called a mollic epipedon, is the defining diagnostic feature of ...
s. These soils have a deep, fertile surface horizon greater than thick. Mollisols characteristically form under grass in climates with moderate to high seasonal precipitation.
Mockernut grows on a variety of soils including wet, fine loams, sandy textured soils that often have been burned, plowed, and pastured.
Alfisol
Alfisols are a soil order in USDA soil taxonomy. Alfisols form in semi-arid to humid areas, typically under a hardwood forest cover. They have a clay-enriched subsoil and relatively high native fertility. "Alf" refers to aluminium (Al) and iron ( ...
s are also present in these areas and contain a medium to high supply of nutrients. Water is available to plants more than half the year or more than three consecutive months during the growing season. On slopes of 25% or less, mockernut grows on wet to moist, fine loam soils with a high carbonate content.
Associated forest cover
Mockernut hickory is associated with the eastern
oak-hickory forest and the
beech-maple forest. The species does not exist in sufficient numbers to be included as a title species in the
Society of American Foresters
The Society of American Foresters (SAF) is a professional organization representing the forestry industry in the United States. Its mission statement declares that it seeks to "advance the science, education, and practice of forestry; to enhance t ...
forest cover types. Nevertheless, it is identified as an associated species in eight cover types. Three of the upland oak types and the bottom land type are subclimax to
climax.
In the central forest upland oak types, mockernut is commonly associated with:
*
pignut hickory (''Carya glabra'')
*
shagbark hickory (''C. ovata'')
*
bitternut hickory (''C. cordiformis'')
*
black oak
Black Oak may refer to:
Places in the United States
* Black Oak, Arkansas
* Black Oak, Daviess County, Indiana
* Black Oak, Lake County, Indiana, a neighborhood of Gary, Indiana
* Black Oak, Missouri
Other
* Black Oak Arkansas
Black Oak Ar ...
(''Quercus velutina'')
*
scarlet oak
''Quercus coccinea'', the scarlet oak, is a deciduous tree in the red oak section ''Lobatae'' of the genus ''Quercus'', in the family Fagaceae.
It is primarily distributed in the central and eastern United States. It occurs on dry, sandy, usuall ...
(''Q. coccinea'')
*
post oak
''Quercus stellata'', the post oak or iron oak, is a North American species of oak in the white oak section. It is a slow-growing oak that lives in dry areas on the edges of fields, tops of ridges also grows in poor soils, and is resistant to r ...
(''Q. stellata'')
*
bur oak
''Quercus macrocarpa'', the bur oak or burr oak, is a species of oak tree native to eastern North America. It is in the white oak section, ''Quercus'' sect. ''Quercus'', and is also called mossycup oak, mossycup white oak, blue oak, or scrub o ...
(''Q. macrocarpa'')
*
blackgum (''Nyssa sylvatica'')
*
yellow-poplar (''Liriodendron tulipifera'')
*
maple
''Acer'' () is a genus of trees and shrubs commonly known as maples. The genus is placed in the family Sapindaceae.Stevens, P. F. (2001 onwards). Angiosperm Phylogeny Website. Version 9, June 2008 nd more or less continuously updated since http ...
s (''Acer'' spp.)
*
white ash (''Fraxinus americana'')
*
eastern white pine (''Pinus strobus'')
*
eastern hemlock
''Tsuga canadensis'', also known as eastern hemlock, eastern hemlock-spruce, or Canadian hemlock, and in the French-speaking regions of Canada as ''pruche du Canada'', is a coniferous tree native to eastern North America. It is the state tree of ...
(''Tsuga canadensis'')
Common understory vegetation includes:
*
flowering dogwood
''Cornus florida'', the flowering dogwood, is a species of flowering tree in the family Cornaceae native to eastern North America and northern Mexico. An endemic population once spanned from southernmost coastal Maine south to northern Florida ...
(''Cornus florida'')
*
sumac
Sumac ( or ), also spelled sumach, is any of about 35 species of flowering plants in the genus ''Rhus'' and related genera in the cashew family (Anacardiaceae). Sumacs grow in subtropical and temperate regions throughout the world, including Eas ...
(''Rhus'' spp.)
* sassafras (''
Sassafras albidum
''Sassafras albidum'' (sassafras, white sassafras, red sassafras, or silky sassafras) is a species of ''Sassafras'' native to eastern North America, from southern Maine and southern Ontario west to Iowa, and south to central Florida and eastern T ...
'')
*
sourwood (''Oxydendrum arboreum'')
*
downy serviceberry (''Amelanchier'' spp.)
*
redbud
''Cercis'' is a genus of about 10 species in the subfamily Cercidoideae of the pea family Fabaceae, native to warm temperate regions. It contains small deciduous trees or large shrubs commonly known as redbuds. They are characterised by si ...
(''Cercis canadensis'')
* eastern hophornbeam (''
Ostrya virginiana
''Ostrya virginiana'', the American hophornbeam, is a species of '' Ostrya'' native to eastern North America, from Nova Scotia west to southern Manitoba and eastern Wyoming, southeast to northern Florida and southwest to eastern Texas. Population ...
'')
*
American hornbeam
''Carpinus caroliniana'', the American hornbeam, is a small hardwood tree in the genus ''Carpinus''. American hornbeam is also known as blue-beech, ironwood, musclewood and muscle beech. It is native to eastern North America, from Minnesota and ...
(''Carpinus caroliniana'')
Mockernut is also associated with:
* wild grapes (''
Vitis
''Vitis'' (grapevine) is a genus of 79 accepted species of vining plants in the flowering plant family Vitaceae. The genus is made up of species predominantly from the Northern Hemisphere. It is economically important as the source of grapes, ...
'' spp.)
* rosebay rhododendron (''
Rhododendron maximum
''Rhododendron maximum'' — its common names include great laurel, great rhododendron, rosebay rhododendron, American rhododendron and big rhododendron — is a species of ''Rhododendron'' native to the Appalachians of eastern North America, fr ...
'')
* mountain-laurel (''
Kalmia latifolia
''Kalmia latifolia'', the mountain laurel, calico-bush, or spoonwood, is a species of flowering plant in the heath family Ericaceae, that is native to the eastern United States. Its range stretches from southern Maine south to northern Florida, ...
'')
*
greenbriers (''Smilax'' spp.)
*
blueberries (''Vaccinium'' spp.)
* witch-hazel (''
Hamamelis virginiana
''Hamamelis virginiana'', known as witch-hazel, common witch-hazel, and American witch-hazel, is a species of flowering shrub native to eastern North America, from Nova Scotia west to Minnesota, and south to central Florida to eastern Texas.
Des ...
'')
* spicebush (''
Lindera benzoin'')
* New Jersey tea (''
Ceanothus americanus'')
* wild hydrangea (''
Hydrangea arborescens
''Hydrangea arborescens'', commonly known as smooth hydrangea, wild hydrangea, sevenbark, or in some cases, sheep flower, is a species of flowering plant in the family Hydrangeaceae. It is a small- to medium-sized, multi-stemmed, deciduous shr ...
'')
*
tick-trefoil (''Desmodium'' spp.)
* bluestem (''
Andropogon'' spp.)
* poverty oatgrass (''
Danthonia spicata'')
*
sedge
The Cyperaceae are a family of graminoid (grass-like), monocotyledonous flowering plants known as sedges. The family is large, with some 5,500 known species described in about 90 genera, the largest being the "true sedges" genus '' Carex'' ...
s (''Carex'' spp.)
* pussytoes (''
Antennaria'' spp.)
*
goldenrod
Goldenrod is a common name for many species of flowering plants in the sunflower family, Asteraceae, commonly in reference to the genus '' Solidago''.
Several genera, such as '' Euthamia'', were formerly included in a broader concept of the gen ...
(''Solidago'' spp.)
* asters (''
Aster'' or other genera, depending on the classification).
In the southern forest, mockernut grows with:
* shortleaf pine
* loblolly pine
* pignut hickory
* gums
* oaks
* sourwood
*
winged elm (''Ulmus alata'')
* flowering dogwood
* redbud
* sourwood
*
persimmon
The persimmon is the edible fruit of a number of species of trees in the genus '' Diospyros''. The most widely cultivated of these is the Oriental persimmon, ''Diospyros kaki'' ''Diospyros'' is in the family Ebenaceae, and a number of non-per ...
(''Diospyros uirginiana'')
* eastern redcedar (''
Juniperus virginiana
''Juniperus virginiana'', also known as red cedar, eastern red cedar, Virginian juniper, eastern juniper, red juniper, and other local names, is a species of juniper native to eastern North America from southeastern Canada to the Gulf of Mexico a ...
'')
* sumacs
*
hawthorns (''Crataegus'' spp.)
* blueberries
*
honeysuckle
Honeysuckles are arching shrubs or twining vines in the genus ''Lonicera'' () of the family Caprifoliaceae, native to northern latitudes in North America and Eurasia. Approximately 180 species of honeysuckle have been identified in both conti ...
(''Lonicera'' spp.)
* mountain-laurel
* viburnums
* greenbriers
* grapes
In the loblolly pine-hardwood type in the southern forest, mockernut commonly grows in the upland and drier sites with:
*
white oak
The genus ''Quercus'' contains about 500 species, some of which are listed here. The genus, as is the case with many large genera, is divided into subgenera and sections. Traditionally, the genus ''Quercus'' was divided into the two subgenera ''C ...
(''Quercus alba'')
* post oak
*
northern red oak
''Quercus rubra'', the northern red oak, is an oak tree in the red oak group (''Quercus'' section ''Lobatae''). It is a native of North America, in the eastern and central United States and southeast and south-central Canada. It has been intro ...
(''Q. rubra'')
*
southern red oak (''Q. falcata'')
* scarlet oak
* shagbark and pignut hickories
* blackgum
* flowering dogwood
* hawthorn
* sourwood
* greenbrier
* grape
* honeysuckle
* blueberry
In the southern bottom lands, mockernut occurs in the swamp chestnut oak-cherrybark oak type along with:
*
green ash
''Fraxinus pennsylvanica'', the green ash or red ash, is a species of ash native to eastern and central North America, from Nova Scotia west to southeastern Alberta and eastern Colorado, south to northern Florida, and southwest to Oklahoma and e ...
(''Fraxinus pennsylvanica'')
*
white ash
* shagbark
*
shellbark hickory (''Carya laciniosa'')
* bitternut hickories
* white oak
* delta post oak (''
Quercus stellata
''Quercus stellata'', the post oak or iron oak, is a North American species of oak in the white oak section. It is a slow-growing oak that lives in dry areas on the edges of fields, tops of ridges also grows in poor soils, and is resistant to r ...
'' var. ''paludosa'')
*
Shumard oak (''Q. shumardii'')
* blackgum.
Understory trees include:
*
American pawpaw (''Asimina triloba'')
* flowering dogwood
*
painted buckeye (''Aesculus sylvatica'')
* American hornbeam
* devils-walking stick (''
Aralia spinosa
''Aralia spinosa'', commonly known as devil's walking stick, is a woody species of plant in the genus ''Aralia'', family Araliaceae, native to eastern North America. The various names refer to the viciously sharp, spiny stems, petioles, and even ...
'')
* redbud
*
American holly
''Ilex opaca'', the American holly, is a species of holly, native to the eastern and south-central United States, from coastal Massachusetts south to central Florida, and west to southeastern Missouri and eastern Texas.
Description
''Ilex opaca ...
(''Ilex opaca'')
*
Dwarf palmetto (''Sabal minor'')
*
Coastal plain willow (''Salix caroliniana'')
Life history
Reproduction and early growth
Flowering and fruiting
Mockernut hickory is
monoecious - male and female flowers are produced on the same tree. Mockernut male flowers are
catkins about long and may be produced on branches from
axils of leaves of the previous season or from the inner scales of the terminal buds at the base of the current growth. The female flowers appear in short spikes on
peduncles terminating in shoots of the current year. Flowers bloom in the spring from April to May, depending on latitude and weather. Usually the male flowers emerge before the female flowers. Hickories produce very large amounts of pollen that is dispersed by the wind.
Fruits are solitary or paired and globose, ripening in September and October, and are about long with a short necklike base. The fruit has a thick, four-ribbed husk thick that usually splits from the middle to the base. The nut is distinctly four-angled with a reddish-brown, very hard shell thick containing a small edible
kernel
Kernel may refer to:
Computing
* Kernel (operating system), the central component of most operating systems
* Kernel (image processing), a matrix used for image convolution
* Compute kernel, in GPGPU programming
* Kernel method, in machine learn ...
.
Seed production and dissemination
The seed is dispersed from September through December. Mockernut hickory requires a minimum of 25 years to reach commercial seed-bearing age. Optimum seed production occurs from 40 to 125 years, and the maximum age listed for commercial seed production is 200 years.
Good seed crops occur every two to three years with light seed crops in intervening years. Around 50 to 75% of fresh seed will germinate. Fourteen mockernut hickory trees in southeastern Ohio produced an average annual crop of 6,285 nuts for 6 years; about 39% were sound, 48% aborted, and 13% had insect damage.
Hickory shuckworm (''Laspeyresia caryana'') is probably a major factor in reducing germination.
Mockernut hickory produces one of the heaviest seeds of the hickory species; cleaned seeds range from 70 to 250 seeds/kg (32 to 113/lb). Seed is disseminated mainly by gravity and wildlife, particularly squirrels. Birds also help disperse seed. Wildlife such as squirrels and chipmunks often bury the seed at some distance from the seed-bearing tree.
Seedling development
Hickory seeds show embryo dormancy that can be overcome by
stratification
Stratification may refer to:
Mathematics
* Stratification (mathematics), any consistent assignment of numbers to predicate symbols
* Data stratification in statistics
Earth sciences
* Stable and unstable stratification
* Stratification, or st ...
in a moist medium at 1 to 4 °C (33° to 40 °F) for 30 to 150 days. When stored for a year or more, seed may require stratification for only 30 to 60 days. Hickory nuts seldom remain viable in the ground for more than I year. Hickory species normally require a moderately moist seedbed for satisfactory seed germination, and mockernut hickory seems to reproduce best in moist
duff. Germination is
hypogeal
Hypogeal, hypogean, hypogeic and hypogeous (; ) are biological terms describing an organism's activity below the soil surface.
In botany, a seed is described as showing hypogeal germination when the cotyledons of the germinating seed remai ...
.
Mockernut seedlings are not fast-growing. The height growth of mockernut seedlings observed in the Ohio Valley in the open or under light shade on red clay soil was:
Vegetative reproduction
True hickories sprout prolifically from stumps after cutting and fire. As the stumps increase in size, the number of stumps that produce sprouts decreases; age is probably directly correlated to stump size and sprouting. Coppice management is a possibility with true hickories. True hickories are difficult to reproduce from cuttings. Madden discussed the techniques for selecting, packing, and storing hickory propagation wood. Reed indicated that the most tested hickory species for root stock for pecan hickory grafts were mockernut and water hickory (''
Carya aquatica'').
However, mockernut root stock grew slowly and reduced the growth of pecan tops. Also, this graft seldom produced a tree that bore well or yielded large nuts.
Sapling and pole stages to maturity
Growth and yield
Mockernut hickory is a large, true hickory with a dense crown. This species occasionally grows to about tall and in
diameter at breast height
Diameter at breast height, or DBH, is a standard method of expressing the diameter of the trunk or bole of a standing tree. DBH is one of the most common dendrometric measurements.
Tree trunks are measured at the height of an adult's breast ...
(dbh), but heights and diameters usually range from about , respectively.
The relation of height to age is:
The current annual growth of mockernut hickory on dry sites is estimated at about 1.0 m³/ha (15 ft³/acre). In fully stocked stands on moderately fertile soil2.1 m³ /ha (30 ft³ /acre) is estimated, though annual growth rates of 3.1 m³/ha (44 ft³/acre) were reported in Ohio (26). Greenwood and bark weights for commercial-size mockernut trees from mixed hardwoods in Georgia are available for total tree and saw-log stems to a 4-inch top for trees 5 to 22 inches d.b.h..
Available growth data and other research information are summarized for hickory species, not for individual species. Trimble compared growth rates of various Appalachian hardwoods including a hickory species category dominant-codominant hickory trees in dbh on good oak sites grew slowly compared to northern red oak, yellow-poplar,
black cherry
''Prunus serotina'', commonly called black cherry,World Economic Plants: A Standard Reference, Second Edition'. CRC Press; 19 April 2016. . p. 833–. wild black cherry, rum cherry, or mountain black cherry, is a deciduous tree or shrub of the ...
(''Prunus serotina''), and
sugar maple
''Acer saccharum'', the sugar maple, is a species of flowering plant in the soapberry and lychee family Sapindaceae. It is native to the hardwood forests of eastern Canada and eastern United States. Sugar maple is best known for being the prim ...
(''Acer saccharum''). Hickories were in the white oak,
sweet birch
''Betula lenta'' (sweet birch, also known as black birch, cherry birch, mahogany birch, or spice birch) is a species of birch native to eastern North America, from southern Maine west to southernmost Ontario, and south in the Appalachian Mounta ...
(''Betula lenta''), and
American beech (''Fagus grandifolia'') growth-rate category. Dominant-codominant hickory trees grew about dbh per year compared to for the moderate-growth species (black cherry) and for the faster-growing species (yellow-poplar and red oak). Equations are available for predicting merchantable gross volumes from hickory stump diameters in Ohio. Also, procedures are described for predicting diameters and heights and for developing volume tables to any merchantable top diameter for hickory species in southern Illinois and West Virginia. Generally,
epicormic branching is not a problem with hickory species, but a few branches do occur.
Rooting habit
True hickories such as mockernut develop a long
taproot
A taproot is a large, central, and dominant root from which other roots sprout laterally. Typically a taproot is somewhat straight and very thick, is tapering in shape, and grows directly downward. In some plants, such as the carrot, the taproo ...
with few laterals. Early root growth is primarily into the taproot, which typically reaches a depth of during the first year. Small laterals originate along the taproot, but many die back during the fall. During the second year, the taproot may reach a depth of , and the laterals grow rapidly. After 5 years, the root system attains its maximum depth, and the horizontal spread of the roots is about double that of the crown. By age 10, the height is four times the depth of the taproot.
Reaction to competition
At certain times during its life, mockernut hickory may be variously classified as
tolerant to intolerant. Overall it is classified as intolerant of shade. It recovers rapidly from suppression and is probably a climax species on moist sites.
Silvicultural practices for managing the oak-hickory type have been summarized. Establishing the seedling origin of hickory trees is difficult because of seed predators. Although infrequent bumper seed crops usually provide some seedlings, seedling survival is poor under a dense canopy. Because of prolific sprouting ability, hickory reproduction can survive browsing, breakage, drought, and fire. Top dieback and resprouting may occur several times, each successive shoot reaching a larger size and developing a stronger root system than its predecessors. By this process, hickory reproduction gradually accumulates and grows under moderately dense canopies, especially on sites dry enough to restrict reproduction of more tolerant, but more fire or drought-sensitive species.
Wherever adequate hickory advance reproduction occurs,
clearcutting results in new sapling stands containing some hickories. Reproduction is difficult to attain if advance hickory regeneration is inadequate, though; then clearcutting will eliminate hickories except for stump sprouts. In theory, light thinnings or
shelterwood cuts can be used to create advance hickory regeneration, but this has not been demonstrated.
Damaging agents
Mockernut hickory is extremely sensitive to fire because of the low insulating capacity of the hard, flinty bark. It is not subject to severe loss from disease. The main fungus of hickory is ''Poria spiculosa'', a trunk rot. This fungus kills the bark, which produces a canker, causes heart rot and decay, and can seriously degrade the tree. Mineral streaks and
sapsucker
The sapsuckers are species of North American woodpeckers in the genus ''Sphyrapicus''.
Taxonomy and systematics
The genus ''Sphyrapicus'' was introduced in 1858 by the American naturalist Spencer Baird with the yellow-bellied sapsucker (''Sphyr ...
-induced streaks also degrade the lumber. In general, the hard, strong, and durable wood of hickories makes them relatively resistant to decay fungi. Most fungi cause little, if any, decay in small, young trees.
Common foliage diseases include leaf mildew and witches' broom (''
Microstroma juglandis''), leaf blotch (''
Mycosphaerella dendroides''), and pecan scab (''
Cladosporium effusum''). Mockernut hickory is host to
anthracnose
A plant canker is a small area of dead tissue, which grows slowly, often over years. Some cankers are of only minor consequence, but others are ultimately lethal and therefore can have major economic implications for agriculture and horticultur ...
(''Gnomonia caryae'').
Nuts of all hickory species are susceptible to attack by the hickory nut weevil (''
Curculio caryae''). Another weevil (''
Conotrachelus aratus
''Conotrachelus aratus'', the hickory shoot curculio, is a species of snout or bark beetle in the family Curculionidae. It is found in North America
North America is a continent in the Northern Hemisphere and almost entirely within ...
'') attacks young shoots and leaf
petioles. The ''Curculio'' species are the most damaging and can destroy 65% of the hickory nut crop. Hickory shuckworms also damage nuts.
The bark beetle (''
Scolytus quadrispinosus
''Scolytus quadrispinosus'', the hickory bark beetle, is a species of typical bark beetle in the family Curculionidae
The Curculionidae are a family of weevils, commonly called snout beetles or true weevils. They are one of the largest animal ...
'') attacks mockernut hickory, especially in drought years and where hickory species are growing rapidly. The hickory spiral borer (''
Argilus arcuatus torquatus'') and the pecan carpenterworm (''
Cossula magnifica'') are also serious insect enemies of mockernut. The hickory bark beetle probably destroys more sawtimber-size mockernut trees than any other insect. The hickory spiral borer kills many seedlings and young trees, and the pecan carpenterworm degrades both trees and logs. The twig girdler (''
Oncideres cingulata'') attacks both small and large trees; it seriously deforms trees by sawing branches. Sometimes, these girdlers cut hickory seedlings near ground level.
Two
casebearers (''Acrobasis caryivorella'' and ''A. juglandis'') feed on buds and leaves; later, they bore into succulent hickory shoots. Larvae of ''A. caryivorella'' may destroy entire nut sets. The living-hickory borer (''
Goes pulcher'') feeds on hickory boles and branches throughout the East. Borers commonly found on dying or dead hickory trees or cut logs include:
* Banded hickory borer (''
Knulliana cincta'')
* Long-horned beetle (''
Saperda discoidea'')
* Apple twig borer (''
Amphicerus bicaudatus'')
* Flatheaded ambrosia beetle (''
Platypus compositus'')
* Redheaded ash borer (''
Neoclytus acuminatus
''Neoclytus acuminatus'', the red-headed ash borer, is a common North American species in the longhorn beetle family (Cerambycidae).
Description and ecology
Red-headed ash borers typically reach adult length, have long antennae which are thic ...
'')
* False powderpost beetle (''
Scobicia bidentata'')
Severe damage to hickory lumber and manufactured hickory products is caused by powderpost beetles (''
Lyctus
Lyctus or Lyttos ( Greek: or ), was one of the most considerable cities in ancient Crete, which appears in the Homeric catalogue. Lyttos is now a village in the municipality of Minoa Pediada.
Lyctus in mythology
According to Hesiod, ''Theogon ...
'' spp. and ''
Polycanon stoutii''). Gall insects (''
Caryomyia'' spp.) commonly infest leaves. The fruit-tree
leafroller (''
Archips argyrospila
''Archips argyrospila'', the fruit-tree leafroller moth, is a moth of the family Tortricidae. It is found in most of the United States and southern Canada.
The length of the forewings is 6-10.2 mm for males and 8.5-11.7 mm for females ...
'') and the hickory leafroller (''
Argyrotaenia juglandana'') are the most common leaf feeders. The giant bark aphid (''
Longistigma caryae'') is common on hickory bark. This aphid usually feeds on twigs and can cause branch mortality. The European fruit
lecanium (''
Parthnolecanium corni'') is common on hickories.
Mockernut is not easily injured by ice glaze or snow, but young seedlings are very susceptible to frost damage. Many birds and animals feed on the nuts of mockernut hickory. This feeding combined with insect and disease problems eliminates the annual nut production, except during bumper seed crop years.
Ecology and uses
Mockernuts are preferred mast for wildlife, particularly squirrels, which eat green nuts. Black bears, foxes, rabbits, beavers, and white-footed mice feed on the nuts, and sometimes the bark. The white-tailed deer browse on foliage and twigs and also feed on nuts. Hickory nuts are a minor source of food for ducks, quail, and turkey.
Mockernut hickory nuts are consumed by many species of birds and other animals, including wood duck, red-bellied woodpecker, red fox, squirrels, beaver, eastern cottontail, eastern chipmunk, turkey, white-tailed deer, white-footed mice, and others. Many insect pests eat hickory leaves and bark. Mockernut hickories also provide cavities for animals to live in, such as woodpeckers, black rat snakes, raccoons, Carolina chickadees, and more. They are also good nesting trees, providing cover for birds with their thick foliage. Animals help disperse seeds so that new hickories can grow elsewhere. Chipmunks, squirrels, and birds do this best. Some fungi grow on mockernut hickory roots, sharing nutrients from the soil.
[''Mockernut hickory.'' (n.d.). Retrieved from http://www.fcps.edu/islandcreekes/ecology/mockernut_hickory.htm ]
True hickories provide a large portion of the high-grade hickory used by industry. Mockernut is used for lumber,
pulpwood,
charcoal, and other fuelwood products. Hickory species are preferred species for fuelwood consumption. Mockernut has the second-highest heating value among the species of hickories. It can be used for
veneer, but the low supply of logs of veneer quality is a limiting factor.
Mockernut hickory is used for tool handles requiring high shock resistance. It is used for ladder rungs, athletic goods, agricultural implements, dowels, gymnasium apparatus, poles, shafts, well pumps, and furniture. Lower-grade lumber is used for pallets, blocking, etc. Hickory sawdust, chips, and some solid wood are often used by packing companies to smoke meats;
[Miller, J.H., & Miller, K.V. (1999). ''Forest plants of the southeast and their wildlife uses''. Champaign, IL: Kings Time Printing.] mockernut is the preferred wood for smoking hams.
[ Though mockernut kernels are edible, they are rarely eaten by humans because of their size and because they are eaten by squirrels and other wildlife.]
Genetics
Mockernut is a 64-chromosome species, so rarely crosses with 32-chromosome species such as pecan or shellbark hickory. No published information exists concerning population or other genetic studies of this species. Efforts are currently underway to map the genome of pecan in a collaborative effort. The genome map at some point may expand to cover other hickory species.
Hickories are noted for their variability, with many natural hybrids known among North American ''Carya'' species. Hickories usually can be crossed successfully within the genus. Geneticists recognize that mockernut hickory hybridizes naturally with C. illinoensis (''Carya'' x ''schneckii'' Sarg.) and C. ovata (''Carya'' x ''collina'' Laughlin). Mockernut readily hybridizes with tetraploid C. texana. Hybrids generally are shy nut producers or produce nuts that are not filled with a kernel. Numerous exceptions to this rule are known.
Gallery
File:Carya tomentosa.jpg, Bud break
File:Carya tomentosa female flower.jpg, Female flower
File:CaryaTomentosaBark.jpg, Bark
References
Sources
*Baker, Frederick S. 1949. A revised tolerance table. Journal of Forestry 47:179-181.
*Baker, Whiteford L. 1972. Eastern forest insects. U.S. Department of Agriculture, Miscellaneous Publication 1175. Washington, DC. 642 p.
*Berry, Frederick H., and John A. Beaton. 1972. Decay causes little loss in hickory. USDA Forest Service, Research Note NE-152. Northeastern Forest Experiment Station, Broomall, PA. 4 p.
*Bonner, F. T., and L. C. Maisenhelder. 1974. Carya Nutt. Hickory. In Seeds of woody plants of the United States. p. 269-272. C. S. Schopmeyer, tech. coord. U.S. Department of Agriculture, Agriculture Handbook 450. Washington, DC.
*Campbell, W. A., and A. F. Verrall. 1956. Fungus enemies of hickory. USDA Forest Service, Hickory Task Force Report 3. Southeastern Forest Experiment Station, Asheville, NC. 12 p.
*Clark, Alexander, III, and W. Henry McNab. 1982. Total tree weight tables for mockernut hickory and white ash in north Georgia. Research Division Georgia Forestry Commission, Georgia Forest Research Paper 33. 11 p.
*Crawford, Hewlette S., R. G. Hooper, and R. F. Harlow. 1976. Woody plants selected by beavers in the Appalachian Ridge and Valley Province. USDA Forest Service, Research Paper NE-346. Northeastern Forest Experiment Station, Broomall, PA. 6 p.
*Cruikshank, James W., and J. F. McCormack. 1956. The distribution and volume of hickory timber. USDA Forest Service, Hickory Task Force Report 5. Southeastern Forest Experiment Station, Asheville, NC. 12 p.
*Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Society of American Foresters, Washington, DC. 148 p.
*Fernald, Merritt L. 1950. Gray's manual of botany. Eighth ed. American Book Company, New York. 1632 p.
*Halls, Lowell K., ed. 1977. Mockernut history, Carya tomentosa. In Southern fruit producing woody plants used by wildlife. p. 142-143. USDA Forest Service, General Technical Report SO-16. Southern Forest Experiment Station, New Orleans, LA.
*Heiligmann, Randall B., Mark Golitz, and Martin E. Dale. 1984. Predicting board-foot tree volume from stump diameter for eight hardwood species in Ohio. Ohio Academy Science 84:259-263.
*Hepting, George H. 1971. Diseases of forest and shade trees of the United States. U.S. Department of Agriculture, Agriculture Handbook 386. Washington, DC. 658 p.
*Jaynes, Richard A. 1974. Hybridizing nut trees. Plants and Gardens 30:67-69.
*Liming, Franklin G., and John P. Johnson. 1944. Reproduction in oak-hickory forest stands in the Missouri Ozarks. Journal of Forestry 42:175-180.
*Little, Elbert L. 1980. The Audubon Society field guide to North American trees, Eastern Region. Alfred A. Knopf, New York. 716 p.
*Lutz, John F. 1955. Hickory for veneer and plywood. USDA Forest Service, Hickory Task Force Report 1. Southeastern Forest Experiment Station, Asheville, NC. 13 p.
*Madden, G. 1978. Selection packing and storage of pecan and hickory propagation wood. Pecan South 5:66-67.
*Madden, G. D., and H. L. Malstrom. 1975. Pecans and hickories. In Advances in fruit breeding. p. 420-438. J. Janick and J. N. Moore, eds. Purdue University, West Lafayette, Indiana.
*Manning, W. E. 1973. The northern limits of the distributions of hickories in New England. Rhodora 75(801):34-35.
*Martin, Alexander C., Herbert S. Zim, and Arnold L. Nelson. 1951. American wildlife and plants. A guide to wildlife food habits. Dover, New York. 500p.
*Mitchell, A. F. 1970. Identifying the hickories. In International Dendrological Society Yearbook. p. 32-34. International Dendrology Society, London, England.
*Myers, Charles, and David M. Belcher. 1981. Estimating total-tree heights for upland oaks and hickories in southern Illinois. USDA Forest Service, Research Note NC-272. North Central Forest Experiment Station, St. Paul, MN. 3 p.
*Nelson, Thomas C. 1959. Silvical characteristics of mockernut hickory. USDA Forest Service, Station Paper 105. Southeastern Forest Experiment Station, Asheville, NC. 10 p.
*Nelson, Thomas C. 1960. Silvical characteristics of bitternut hickory. USDA Forest Service, Station Paper 111. Southeastern Forest Experiment Station, Asheville, NC. 9 p.
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*Wiant, Harry V., and David 0. Yandle. 1984. A taper system for predicting height, diameter, and volume of hardwoods. Northern Journal of Applied Forestry 1:24-25.
External links
''Carya tomentosa'' images at the Arnold Arboretum of Harvard University Plant Image Database
{{Taxonbar, from=Q5047673
tomentosa
Edible nuts and seeds
Trees of the Eastern United States
Trees of the Northeastern United States
Trees of the North-Central United States
Trees of the Southeastern United States
Trees of Ontario
Flora of the Appalachian Mountains