This week for Flora and Fauna Friday it’s one hull of a hardwood, the Mockernut Hickory (Carya tomentosa).
The Mockernut Hickory is a species of Hickory tree found throughout the Southeast and all of South Carolina. It’s highly drought tolerant and much prefers dry soils. It is just as much a common sight on the rocky ridge tops of the foothills and piedmont as it is on the fire pruned savannas of the sandhills, coastal plain, and sea island sand ridges. However, it’s also often found on richer soils that are sufficiently well-drained. This tree can eventually reach a hundred feet in height in forest settings, but generally is closer to seventy-five feet at maturity here in the Lowcountry. Its bark is dark gray, rather thick, and fissured with a blocky net-like pattern. This thick bark allows it to tolerate infrequent fire, although it’s not as fire dependent nor tolerant as many of our trees. Its leaves are compound, most often having seven broad leaflets, notably displaying wooly undersides, and can vary widely in total size from one to two feet in length. Here on the Sea Islands around the latter half of November, Mockernut and our other Hickories will release their fall colors, turning sharp shades of amber-yellow and candle-orange as they shed their leaves. About that same time in late October and throughout November, Mockernut Hickories begin to drop nuts. It’s a massive seed, often an inch wide, inch tall, and three-quarters of an inch thick, with a square profile, broad shoulders, and small point at the tip. The whole seed grows within a rind that is another quarter to three-eighths of an inch thick, making the entire fruit larger than a golf ball and nearly two inches around. This rind is dehiscent, meaning it splits as it dries in order to release the seed, and will itself be shed to the ground in four pieces.
Mockernut gets it common name from its seed. It’s a nut that makes a mockery of anyone who tries to get into it. The hull of a Mockernut seed is a full quarter-inch thick with many deep ridges that furrow the wrinkly, brain-shaped meat within. It’ll take two big rocks for you to get into one. And when you do, more often than not you’ve crushed the entire thing into oblivion. But even if you crack it cleanly, you’ll be granted only a paltry reward of meager nutmeat treats wedged irrecoverably between chunks of hull as hard as cement. Even though Mockernuts are perfectly edible to humans, they are practically impossible to make a living on. But that’s not the case for all wildlife. Mice, Woodrats, and Squirrels can use their ironclad incisors to chisel open the hulls and shell Mockernuts with relative ease. Deer and Turkeys will also gulp them down on occasion, but generally prefer any other nuts when available. These mammoth Mockernut Hickory seeds are primarily dispersed by squirrels, gravity, and floods. Squirrels will haul them up hills to stash for later, often forgetting a few that will later germinate. Trees growing on hilltops drop seeds that then roll downhill and settle on slopes and in valleys. Fall and winter flooding will float Hickory seeds downstream, depositing them inland when floodwaters recede.
What Mockernut Hickory lacks in value to humans as a food source, it makes up for in its value as a timber tree. Mockernut Hickory, being the most abundant Hickory in the Eastern United States, makes up the bulk of the Hickory wood grown and used in the country. Hickory is a stiff, tough wood that resists impacts and cracking very well, all while still being fairly light. This makes it the ideal wood for tool handles, particularly axes, hammers, and shovels that need to absorb a lot of repeated stress. The wood is also prized as a firewood as it burns hot, burns long, produces little smoke, and that smoke smells nice to boot. In fact, the smoke not only smells nice but tastes nice, and is regularly used in smoking and curing meats, particularly pork.
The Mockernut Hickory is one of eight species of Hickory tree found here in the Lowcountry. It shares this landscape with the abundant Pignut Hickory (Carya glabra), Sand Hickory (Carya pallida), Water Hickory (Carya aquatica), Bitternut (Carya cordiformis), and Pecan (Carya illinoinensis) as well as the locally scarce Shagbark Hickory (Carya ovata) and Nutmeg Hickory (Carya myristiciformis). Hickories all share a few common characteristics that make them an easy genus to spot. Their leaves are alternate and pinnately compound, generally with seven to eleven leaflets emerging from the mid-vein. One leaflet emerges from the tip and the remainder as opposing pairs shrinking in size as they get closer to the twig. Their barks tend to have a diamond-weave pattern, with vertical ridges that merge and split from each other, unless obscured in some species by flaky peeling plates. They’re all wind pollinated, and produce inconspicuous green catkin flowers in mid-spring. Their fruits are large, oblong nuts that are usually edible for humans and a dietary staple of many forest rodents. Underground, Hickories seedlings take advantage of their huge seed to grow a deep taproot when they germinate. This not only anchors them to the soil but affords them ready access to the local water table and deep soil nutrients that many other hardwoods can’t reach.
Of all these species, Mockernut Hickory is the most common Hickory you’ll encounter in South Carolina and much of the Eastern United States. However, Pignut Hickory is just as abundant here on the Sea Islands, if not a bit more. Telling a Mockernut from a Pignut is an easy feat. Habitat-wise on the Sea Islands, Pignut Hickory prefers coarser sands and younger soils with a water table readily accessible to their deep taproot. They also grow closer to the coast and can tolerate salt’s influences to a slight degree. Mockernut Hickory and Pignut Hickory are equally-sized trees, each readily attaining a height of seventy feet tall at maturity. At a glance, they look quite similar but differ in the finer details once scrutinized. Mockernut Hickory generally has a thicker, rougher bark toned a darker shade of medium-gray. Whereas Pignut Hickory has a smoother, less blocky barker that’s a paler gray. Their leaves are also a giveaway. Mockernut Hickory leaves are coarsely hairy, especially on the petiole near the base. Pignut Hickory leaves are totally smooth by comparison. This dichotomy is captured in their scientific names, with “Carya tomentosa” meaning “Wooly Hickory” and “Carya glabra” meaning “Smooth Hickory”. Their common names describe another dichotomy found in their fruits. Mockernut seeds are huge, square, and have a very heavy hull, making a “mockery” of anyone who attempts to crack them. Pignut fruits are smaller, more circular, and have a “pig nose” projection at the tip of their rind. Their nuts most often fall from the tree with this rind still attached. However, the name “Pignut” actually describes their historic importance in feeding semi-free-range pigs reared by early colonists, as the nuts are palatable and more readily cracked and digested by livestock compared to the Mockernut.
Sand Hickory is a less common lookalike to Mockernut Hickory found in many of the same habitats on the coast. Picking between a Sand Hickory and a Mockernut Hickory on the Sea Islands can be a difficult task. Both grow on dry sandy soils, have similar bark, and have hairy leaves. Sand Hickory, as a consequence, hides in plain sight and often gets written off as an under-sized Mockernut, even by seasoned ecologists and foresters. However, it’s not an impossible identification. Sand Hickory tends to have a silvery underside to its leaves and Mockernut Hickory instead a brass-colored fuzz below. Sand Hickory also has, on average, smaller leaves and more narrow leaflets. The twigs and buds of Sand Hickory tend to be svelter too. It’s also a smaller tree, generally only growing closer to forty feet tall. Their seeds as well are about two-thirds the size of Mockernut seeds, with a thinner rind and a more circular profile.
