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7 Things You Need To Know About The Pignut Hickory
Why Pignut Hickory?
Effortlessly withstanding gales and making it’s presence felt as our neighborhood shade tree, the pignut hickory surely deserves more recognition and attention. Standing tall at around 50 to 75 feet, one Ohio pignut tree was also measured at 120 feet tall in the 1980s. Pignut trees are slow growing but perennial giants. They are found mostly in Canada, most of eastern United States and eastern Texas. The tree’s connection with humanity is longstanding with reports of pignut hickory cultivation as early as the late 1700s. The scientific nomenclature for American hardwood pignut hickory tree is Carya glabra where Carya indicates it’s connection to the walnut family, the Greek meaning of the word being walnut. Glabra, originating from glabrous basically means smooth and refers to the smoothness of the nut and leaf.
Common names for pignut tree are coast pignut, broom hickory and smoothbark hickory. The name ‘pignut’ seems to have two origins. One is, if you split the nut open in half, it looks like a pig’s snout. The other one is that early US settlers found wild hogs preferred this nut and thus they named it pignut. It is also called broom hickory because supposedly early settlers split the wood up very finely for use as brooms. Whatever the origin of their name, pignut hickories have proved themselves useful to wildlife and humans in more ways than one. Different parts of the tree from flowers, leaves and nuts to saplings and barks, all are relished by a variety of birds and animals. People understood the excellent flexibility and tensile strength of pignut hickory wood way back and used it in building their wagon wheels, harnesses and tools. The dense wood has been acting as firewood for decades. Through root and stump sprouting, these trees can regenerate after being cut down or suffering natural damage. Not only can it sprout effectively, the second harvest pignut hickory wood is considered to be better quality lumber. The pignut tree also creates hybrids with other hickory trees and some of these are so similar to pignut that distinguishing them becomes quite tough. The pignut hickory leaves have quite high calcium content and every fall they enrich the soil around them by adding quality compost. The long sturdy taproot of the tree gives it excellent tree stability and drought hardiness. The flexible and widely spaced branches can withstand gales and hurricanes quite effectively making these long-suffering trees quite remarkable.
7 Identifying Features of Pignut Hickory Tree
Identifying trees in the wild or out in nature requires a decent understanding of their habitat and common features. Getting a clear idea of it’s shape, size, leaf structure, fruit and flower construct, bark anatomy and more helps in identifying a tree with surety. Any knowledge of special characteristics becomes an added advantage making the whole process easier and relatively quicker.
- General appearance: The pignut hickory tree has a straight and strong vertical column that generally doesn’t split at the top, crowned by irregularly dense foliage. This tree grows to a height of about 50 to 75 feet depending on soil and growth conditions. It is known to grow even to 100 feet in height aided by moist soil and favorable weather conditions. Trunk of this slow growing hickory variety grows to about 2 to 3 feet wide. The canopy has a rough oval shape that spreads to a diameter of about 30 to 40 feet. Pignut tree branches, though do not droop, are very flexible and irregularly spaced giving them the space and ability to withstand high speed wind situations like storms and hurricanes. In autumn, the crown takes on a red-tinged orange hue and becomes totally bare in winters.
- Bark: The grey pignut tree bark is comparatively smooth than most other hickory varieties. The shallow and sometimes deeper grooves make a rough diamond pattern. Mature pignut hickory trees have more pronounced grooves on the bark. The ridge edges are rather rounded and not sharp. The bark does not peel off like shagbark or kingnut hickory. The branches and young twigs both have a smooth texture, but while the branches are grey, the twigs are brown. Pignut tree bark like other hickory varieties has elongated tiny little openings to help gas exchange of the internal tissues. The bark is not one of the most easily distinguishable factors from other large tree varieties and mostly relies on leaves and fruits for identification. Raccoons, black bears and rabbits make it a part of their diet. The hickory bark is sometimes used to make organic brown dye.
- Leaf: The pignut hickory leaves are broad, long, and flat with fine serrations on the edges. Common to all hickory varieties, the leaves are compound in pignut trees too. The leaves are about half to one foot long. These most often than not have 5 leaflets per central stalk or rachis and are placed alternately along the stalk. The bottom 2 leaflets farther away from the crown are visibly smaller and about one-third the size of the upper ones. The smaller leaflets are attached directly to the central stalk while the 3 remaining leaflets are attached to it with tiny stalks of their own. Both sides of the leaf are smooth. The color is shiny dark green on the top and paler on the underside. Base area of the central stalk sometimes gets a fuzzy covering. The fallen leaves leave behind a heart-shaped indentation on the twig. The new leaf buds appear just above these scars. Autumn pignut hickory leaves turn red-tinged orange or a less vivid yellow color and not vibrantly yellow like most other hickories. However, a bright red coloration of the foliage would indicate disease and imminent demise of the pignut tree. The pignut leaves like other hickory varieties, have comparatively higher calcium content and improve the quality of soil around them with annual leaf-shed. The leaves along with the fallen twigs make up a part of the white tailed deer’s diet. These pignut hickory leaves also attract a wide variety of beautiful moths like hickory leafroller and luna moth as caterpillar food. The yellow billed cuckoos are attracted to the pignut tree because of the squishy tent caterpillars that are found in their tent-like cocoons among the leaves.
- Flower: The flowers of pignut tree are monoecious meaning both gender flowers grow on the same tree and are pollinated by wind. The unisexual flowers bloom in spring for about 2 weeks but vary from mid March to early June depending on the geographical location. The male flowers tend to appear before the female ones. The greenish yellow flowers are the male varieties occurring as catkins, arranged along a droopy soft stem growing from the terminal buds in their inner scales or at the end of last year’s twig growth. They vary from about 2 to 4 inches in length. The green female pignut flowers are less showy, about a quarter inch long and occur in spikes of 2 to 5 at the end of current year’s twigs. These flowers along with the nuts are relished by many birds including the wild turkey.
- Nut: The husk is oval, slightly flattened, thin and smooth. It retains it’s green color until ready to release the nuts around September or October. At maturity, the husk takes on a light brown color similar to the tan nutshell within. The pignut hickory nut husk can split partially close to the tip into four equal parts or remain intact with the nut. It generally stays attached to the nut even after falling from the tree. The nut shell doesn’t have any ribs like other hickory varieties and is smooth, thick, hard and a bit flattened. The nutmeat is roundish, a bit flattened and is quite pale in color. It is also lighter in weight than other hickory nuts. September to December is pignut yield time. Frost has a tendency to destroy it’s production potential. The pignut hickory nut is liked by many animals and especially by squirrels who help in pignut seed dissemination. The nuts are also enjoyed by chipmunks, black bear, raccoon, gray fox and even the red-billed woodpecker. It isn’t very popular with humans due to the usually bland or bitter taste, though it can sometimes be mildly sweet with a bitter aftertaste. High fat content of the hickory nuts make them especially good for animals looking to stock up before winter hibernation. An interesting fact to note, the pignut tree seeds can usually withstand a single season of winter but need to germinate before reaching the second one. Nut-bearing pignut trees range from 30 to 300 year old. Though nuts are produced every year, good yield occurs mostly every alternate year. Yield also depends on environmental conditions like drought, frost or other natural damage to the tree.
- Terminal bud: These are egg-shaped and appear at twig ends during winter months. They smell wonderfully fresh with a spicy hint when crushed. The terminal bud itself is pale, small measuring less than half an inch long with a short blunt tip. The 2 or 3 scales of the bud are brown to reddish brown in color and overlap each other always keeping one edge visible. These scales with sometimes very fine fuzzy covering open up and can fall off during winter. The yellowish green catkins of pignut hickory tree often use the inner scales of terminal buds to grow in spring. The side buds are positioned at almost 90-degree angle to the stem unlike shagbark hickory leaf buds that form more of an acute angle.
- Root: Though the root of a living tree won’t be visible for identification, having a fair idea of their structure helps in understanding their soil and location preference along with suitability for different purposes. The dominant and deep-reaching strong taproot, gives great stability to these windfirm trees making them gale and hurricane resistant to a large degree. Also, roots can reach far down to moisture-rich soil during droughts helping the tree withstand such harsh conditions. The lateral root system of this variety of hickory is less prominent with a more shallow growth pattern. The pignut seed tends to develop the taproot faster than the part above ground to ensure survival. Root rot is one of the few diseases that has the ability to critically damage pignut trees. Like bitternut hickory, the pignut hickory tree too has the ability of stump as well as root sprouting making regeneration of the tree easier. In lumber harvested trees, the roots tend to show new growth more readily than stumps. The deep-shooting taproots and fungal infection of disturbed roots make the pignut tree quite difficult to transplant successfully and is one of the reasons that these trees aren’t considered suitable for landscape decoration.