This week for Flora and Fauna Friday we have a spindly spidery critter with a superstitious reputation, the Harvestmen of order Opiliones.
Harvestmen are arthropods with quite the folklore surrounding them. I can recall quite a few childhood tales about them. Chief in my memory is how they’re supposed to be the deadliest spider around, save that their fangs are too small to puncture your skin. In contrast to this playground lore of yore, I’m here today to tell you the truths about this interesting arachnid.
Harvestmen belong to the order Opiliones within the Arachnida class. They share no close relation with spiders and are actually most closely related to Scorpions. They’re common throughout our forests and woodlands and often found huddled together in shady crooks of porches and barns. Although they come in many shapes and sizes, their general appearance is distinct and unmistakable. I won’t even pretend that I comprehend their diverse phylogeny but I believe the genus Leiobunum is the clade most of us will recall when imagining the Harvestmen of the Lowcountry; a round pale-brown body composed of a single segment supported in midair on eight articulated wispy legs. Each barely bristle-thick appendage arcing upward from the fringes of that egg-shaped center. Peering ever closer we can see a tiny cluster of beady little eyes front and center, on what passes for a head, and a pair of tiny pincers for a mouth.
Harvestmen move with either a jittering, bouncy gate or a slow purposeful walk, elongated middle limbs out stretched ahead as they feel their way forward. They have a wide and varied diet that differs between species. Most are omnivorous, some are predatory, and others scavengers. They eat their food, alive or dead, animal or vegetable, by picking it apart with their tiny pincer-like mouthparts. Harvestmen are wholly nonvenomous by the way and completely harmless to humans. However, they will release foul smelling chemicals if handled roughly. They also employ autonomy to escape from danger, shedding their wiry legs if they become ensnared. This is a costly move as Harvestmen cannot regrow their limbs and is why you’ll often find them down a leg or two.
This week for Flora and Fauna Friday we have an almost evergreen understory addition to our upland woodlands, Sweetleaf (Symplocos tinctoria).
Sweetleaf, also called Horsesugar, is a large broadleaf shrub native to the Southeastern United States. Sweetleaf is an important addition to our forest ecosystems here on Edisto as it makes up a significant portion of the understory in mature upland forests around the Island. Both of its common names reference the palatability of the leaves to horses and livestock. Some say you can taste the sweetness yourself by breaking the main vein of a fresh leaf and touching it to your tongue, but I’ve never been able to taste it and Lord knows I keep trying. The specific epithet “tinctoria” means dye and the bark of the plant was once used for making a yellow dye.
Sweetleaf grows a distantly liana-like trunk sheathed in pale gray bark, mostly smooth but periodically split with furrows of cinnamon. This lumber lattice lauds large elliptic leathery leaves of emerald green, often weeping wearily when wanting water. These leaves are somewhat evergreen, as some plants will keep their leaves throughout the winter while others shed them all in fall. For as common as Sweetleaf is, its ubiquity and rather generic appearance can make it unsuspectingly difficult to identify if it’s not already on the mind. The easiest time to pick it out is in late winter. About the start of March Sweetleaf starts to bloom and its scant branches begin to glow with fuzzy flowers of cream-white and gold. Sweetleaf is one of our first flowers of the year and this final frost flush helps wake our pollinators from their winter slumber. Those flowers mature into a small, and otherwise insignificant, drupe.
Another easy way to identify Sweetleaf is by a fleshy gall that often afflicts the plant. This gall is caused by the bacterium Exobasidium symploci and it appears on Sweetleaf twigs. The gall is usually silvery blue over a lime-green base color with a rubbery, foam-like appearance. This gall is a physical mutation caused by the Exobasidium bacterium growing within the leaves or flower tissue of the shrub. These galls are generally not a health concern for the plant. However, their alien appearance in often impossible to ignore for those on an idle amble. They stand out like a sore thumb in the barren winter woods.
This week for Flora and Fauna Friday, we have a pair of fluffy butted, big eared, garden guests: the Cottontail Rabbits (genus Sylvilagus).
Rabbits as a whole belong to the order Lagomorpha. Lagomorphs share some superficial similarities to Rodents, as the two orders are closely related, but they’re distinct clades. One of the simpler ways to tell the two orders apart is that rodents have two incisors and rabbits have four. Here on Edisto Island we have two species of rabbit, both of which are members of the Cottontail genus. Both of our rabbits are roughly the size of a football and about the same color. They both inhabit early successional habitat, prefer to feed on fresh vegetation on the edge of open areas, and are most active at night. Rabbits are herbivorous, feeding mainly on forbs. Like White-tailed Deer, they are a prey species and, similarly to deer, rabbits have a physiology built for detection and fleeing. Rabbits have big side-facing eyes and movable cupped ears for sensing predators. These are coupled with long, muscled rear legs that allow them to accelerate rapidly to high speed in order to escape predators. This is why rabbits never tend to stray far from thickets or other dense cover.
The Eastern Cottontail (Sylvilagus floridanus) is your common rabbit found in a wide range of habitat throughout the eastern half of the United States. They’re most often found in fields, yards, roadsides, and other open habitats. They have a brindled coat of white, tan, and black fur, large beady black eyes, tall elliptical ears, and a conspicuous cottony tail. In general, they have a round shape to their head and a somewhat boney appearance. The Marsh Rabbit (Sylvilagus palustris) is found throughout the coastal plain of the southeast and is partial to marshy wetland habitats. They are quite common on the Sea Islands in maritime forests surrounding tidal marsh. Marsh rabbits have fur that is brindled primarily in browns and black, small eyes, short circular ears, and they like to keep their tail tucked away. Marsh Rabbits usually have a triangular-shaped head and a plump, guinea-pig-like appearance.
This week for Flora and Fauna Friday we have ancient acid-loving, artifact-saving, and amendment making plant to dig into, Peat Moss (Sphagnum spp.).
Peat Moss, or Sphagnum Moss, is a genus of mosses found across the globe. Edisto is no exception. These mosses love wet, acidic soils and are tolerant of drought, flooding, and extreme temperatures. So the Lowcountry sounds like a perfect home! Sphagnum does best in wet places where little else can grow. You’ll most often find them in Carolina bays, on the edges of permanent wetlands, wet depressions on highly acidic soils, ditch edges, and sometimes in the crooks of tree roots. When conditions are right, the moss can form perpetual peat bogs. Large patches of moss positioned atop deep beds of decaying peat. Peat bogs can be quite extensive and extremely deep in colder climates but tend to be much more modest in South Carolina.
Sphagnum moss comes in many shapes, sizes, and colors but all share a similar structure. It is low growing with a shaggy, lumpy form. Sphagnum is best recognized by it tufted, carpet-like appearance. Each branch of the stem is whorled in often toothed tufts of green flesh. Peat moss is different than most of the plants we’re familiar with. It belongs to the ancient group of plants called the bryophytes, to which all true mosses belong. Bryophytes are the most ancient of land plants. They are so primitive that they spread by spores and even lack vasculature structures. All water must move passively through the plant. This is why Sphagnum loves wet conditions. Yet this character is also the source of its drought tolerance. Since it can’t rely on roots or vasculature to find and pump water throughout its body, peat moss is built like a living sponge. It can store many times its weight in water in order to weather through droughts. However, it also means that it can’t grow very tall or very thick, as the further away a part of the plant is from soil moisture, the less chance it has to survive.
Throughout human history, Sphagnum has had many important uses in human society and commerce. Anaerobic peat bogs in Europe were once used for food storage, as the old, acidic, low-oxygen conditions of some bogs allowed fat rich foods like butter and lard to last almost indefinitely. In much the same manner, peat bogs can also preserve animals and organic artifacts for millennia. Some bogs have yielded stupendous findings for both ecologists and anthropologists. The accumulated dead peat within Sphagnum bogs also has many unique and useful properties. Peat can be mined and dried for several purposes. Bricks of dried peat can be burned as a commercial fuel source or stacked as a primitive insulating building material. This same peat can be shredded to create a powerful soil amendment that dramatically improves the water and nutrient holding capacity of mineral soils. Shredded peat moss, when dried, is highly absorptive and strongly acidic. These traits make it great at staunching bacteria and mold growth. These traits have not been overlooked and it has been used for centuries for moisture control when packing perishable materials, absorbent baby diapers, and even as sterile wound dressings! You may have also heard of the short-lived peat mines here in the ACE Basin. These operations mined a different kind of organic material, also called peat, which originated beneath our bottomland forests, not the kind produced by Sphagnum.
This week for Flora and Fauna Friday we have a very important member of our local ecosystem that we all have seen but only a few recognized: ectomycorrhizal fungi.
Now, mycorrhizal fungi are not a specific clade of fungi. They’re a group of fungi who play a similar role in the ecosystem. That role is a mutualistic relationship with plants, most easily observed in the wild on trees. The plant and the fungus work together and the partnership is a win for both organisms. Mycorrhizal fungi are a critical link in the nutrient cycle and, without them, timber production and forest vigor would be far reduced in many parts of the world. Many of the mushrooms you commonly see, such as Amanitas, Russalas, and Boletes, are mycorrhizal fungi and so are many prized edible mushroom like Chanterelles, Milkcaps, Black Trumpets, and Truffles.
Mycorrhizal fungi live underground. The mycorrhizal relationship happens in the soil at the roots of the plant. The term mycorrhizae literally means “fungus-root” in Latin. Here the hyphae of the fungus and the roots of the plant “hold hands” and form a complex interconnected network of roots. The fungi can then act as an extension of the plant’s root system. This gives the plant a new source of hard to get nutrients and water that the fungus’ hyper-fine hyphae can suss out of the soil and that its specialized enzymes can pull out of detritus. In exchange, the plant feeds the fungus sugars and other carbohydrates that it produced through photosynthesis. Together the two organisms prosper. The plant has better access to nutrition and the fungus gets something to eat other than dirt and sticks.
There are two general groups of mycorrhizal fungi which are defined by how they interact with the plant. They are endomycorrhiza and ectomycorrhiza. The prior can be broken down further into Arbuscular and Ericoid but we’ll save that for another day. The main difference is that endomycorrhizal fungi live inside the cells of the plant’s roots and ectomycorrhizal fungi live outside the plants roots. I’ll mainly be talking about ectomycorrhizal fungi today. However, just know that endomycorrihzal species are far more common and associate with many more plant species. Yet, they’re much harder to observe and are obligate symbionts, meaning they can’t survive for long without a host plant to attach to. Ectomycorrhizal fungi on the other hand are usually not dependent on a host. They can live freely in the soil as a saprotrophic fungi. (Fungi that get their meals by digesting detritus and rotting plant material in the soil.) These ectomycorrhizal fungi generally associate with woody plants, like shrubs and trees, and are also the species that produce the highly visible, and sometimes edible, mushrooms we often see scattered across the forest floor. Their saprotrophic abilities combined with their mycorrhizal relationship allow them to speed up the nutrient cycle in forest ecosystems. Fast tracking nutrients, that would otherwise be locked up in leaf litter, back into the trees. This makes forests more resilient allowing them to better respond to and recover from logging or natural disasters.
We’re happy to report that the National Trust for Historic Preservation has featured the Hutchinson House on the cover of their most recent Winter, 2021 issue of Preservation Magazine.
This week for Flora and Fauna Friday is our big water weasel: the North American River Otter (Lontra canadensis).
Weighing in at roughly fifteen pounds and three foot long, River Otters are our biggest member of the weasel family. Their pelt is dense and oily-brown across their long, serpentine body. Their legs short and stocky with wide, webbed toes. Their tail is long and broad, thick with muscle as it tapers to the tip. Their tiny ears, long whiskers, beaded eyes, and round dark nose give them an indisputable teddy bear demeanor and cat-like elegance. River Otters use their broad tails, long bodies, and webbed feet to shuttle through the water and wrestle with fish. Their long whiskers let them feel prey in the dark, muddy waters they hunt. Their diet is entirely carnivorous, with their preference being fish, then crustaceans. They will also eat ducklings, frogs, and rails if encountered. In freshwater, their main predator is the American Alligator.
They’re chiefly nocturnal and cycle through their favorite haunts in our creeks, salt marshes, ponds, and swamps over the course of the night. They show little preference for salt or not on Edisto. River Otters are an intelligent and social aquatic mammal that’s prone to fits of frolicking and curiosity as it stalks our creeks and warily watches us from the water’s surface. They travel in small family groups of a few Otters a piece and can be heard in the dead of night grunting, splashing, slipping, and sliding over mud and berm as they roughhouse, slither, and gallop through the brush. Often, the only signs we ever see of their presence are webbed footprints, muddy tail drags, and a scattering of fish scales across a trail.
This week for Flora and Fauna Friday we have a common woodland Orchid most easily spotted by its evergreen winter foliage, Cranefly Orchid (Tipularia discolor).
Cranefly Orchid is a native Orchid found often across South Carolina where it grows on rich and moist forested upland soils. They are perennial and grow below the soil with spreading corms to form small stands of plants. These corms are edible but neither substantial nor particularly flavorful. Cranefly Orchids bloom in midsummer producing a foot and half tall stalk of flowers. This flower stalk is sparsely populated by five-petalled, cream-white, lanky and downturned blossoms. The flowers are named for their Cranefly-esque traits. (Craneflies, AKA Skeeter-Eaters, are large scrawny flies that superficially resemble giant Mosquitoes. More on them at a later date.) The flowers are pollinated by moths and mature into small urn-like seed pods. These tiny pods are filled with thousands of spore-like, nearly microscopic seeds. These nigh weightless seeds are dispersed by wind. The flower stalks dry and can remain through winter.
Cranefly Orchids are unique for their leaves. The leaves emerge in fall, persist through winter, and wither away before the plant blooms. A single leaf is produced per corm. The physical appearance of the leaf is unique as well. The leaves are teardrop shaped, roughly three inches long, and lay atop the leaf litter on the forest floor. They have parallel veins and often a bumpy appearance. The upper surface of the leaf is a dark green and its bumps are sometimes accented by amethyst spots. The underside of the leaf, by contrast, is a rich royal-purple and usually shiny. The purpose of this pigmentation is not fully understood. One hypothesis suspects the purple helps absorb the sparse winter light and infrared radiation from the soil to protect the frigid leaf from sun damage and heat the leaf to improve photosynthesis efficiency. Regardless, the Cranefly Orchid has found an interesting niche in our forest ecosystems. Rather that compete for light between the shadows of the summer canopy, it simply waits until winter and stores energy for the following summer.
This week for Flora and Fauna Friday we have an oversized icy-white snowbird, the Tundra Swan (Cygnus columbianus).
Tundra Swans are tied with the Wild Turkey for the heaviest bird in South Carolina, sometimes tipping the scales at over 20 pounds. Their impressive five foot wingspan is nearly matched by their four to five foot length. Swans are unmistakable. Their general bigness and solid pearl-white plumage above sturdy black legs puts them in a category of waterfowl all their own. Within the swans we may perchance see three species: Mute Swan (C. olor), Trumpeter Swan (C. buccinator), and Tundra Swan. Tundra Swans are our only regular visitor but the others appear on occasion. The three species can be distinguished by their bill and their build. Mute Swans are native to Europe and the species you’ll see cruising around urban ponds. However, some have escaped into the wild and can occasionally come south to mingle with our Tundra swans. Mute Swans can be identified by their orange bill with a forehead hump. Trumpeter Swans are the largest waterfowl native to North America but only very very rarely come so far South as Edisto. Trumpeter Swans can be identified by their solid black bill and usually rusty head. Tundra Swans are significantly smaller on average than the other two but this size difference isn’t always obvious. Tundra Swans are best distinguished by a patch of saffron-yellow skin beside the eye. Tundra Swans spend the winter here in small flocks on the managed impoundments repurposed from historic rice fields. Here they feed on submerged vegetation alongside a myriad of ducks and the similarly sized American White Pelicans.
Swans are a waterfowl not often associated with the Lowcountry but every year we are visited by a humble caravan of the graceful fowl here in the ACE Basin. I’ve spent many a frigid January morning along the Edisto tiptoeing down a causeway before day breaks. Shuffling into place as the first light of dawn illuminates humidity hanging above an impounded marsh. With the earliest flicker of sunrise the Swans awaken. I am swept up by echoing exclamatory single syllable vibratos. As sunrise intensifies so does the sound and as the fog begins to evaporate the Tundra Swans materialize. Icebergs of white buoy and beacon above the dreary landscape of murky pools and lifeless reeds. They propel themselves effortless along the water with nary a ripple and move their slender necks with angelic elegance. Distant notes approach as a formation of Swans signal their own arrival. Wings flail like flags in a gale along a somehow stable fuselage. Like a flurry they descend to melt upon the water. The aviators kick out their landing gear – heels forward, wings wide – and ski to idle speed. Tundra Swans are by no means common in our state but we are blessed here in the ACE Basin to see them every year. I do not often find them on our Island, as their destination is often a short ways beyond the South Edisto River, but I relish the sight whenever I do.
This week for Flora and Fauna Friday we have a thin porcelain-skinned nut-bearing tree, American Beech (Fagus grandifolia).
American Beech is a common tree in floodplain forests, where it relishes the moist soils rich in nutrition from periodic floods. Yet Beech does not grow well on the soggy soils of the bottomlands, sticking to the higher and drier soils of the upper floodplain. American Beech is a beautiful and unmistakable tree. Its marble-white bark puckers like goosebumps and wrinkles like muslin as it conforms like skin to its muscle furrowed trunk. This skin extends to shallow roots that often grow down over obstacles and up into a buttress. This bark in and of itself distinguishes the Beech from its Lowcountry surroundings on all but our whitest winter days. Yet on those scarce snowy mornings Beech still stands apart from its neighbors. American Beech is unique in that it holds onto its fall foliage until spring. Although thoroughly brown and devoid of life, last year’s leaves remain until new buds break. This makes Beeches easy to spot from the roadside on a frigid winter drive. Beyond the zombie leaves lies another novel feature, the bud. Beech buds are easy to ID as they are unusually long and slender, sometimes a full inch in length. These oversized buds break in fall to quickly produce a new twig with leaves. The leaves of American Beech are moderately large and elliptical with a dentate margin. Dentate leaves have a regularly toothed margin like the blade of a saw. American Beech also produces edible nuts. These nuts ripen inside a coarsely hairy pod that splits in four to dispose of the nuts within. Each pod contains two or three nuts and each nut is teardrop-shaped and triangular in cross-section.
Beech trees are a species known for strong mast reproduction. Mast reproduction is a phenomenon of many nut bearing trees and shrubs. Unlike plants that produce berries or other soft fruits, nut bearing trees do not want animals eating their fruit. When an animal eats a soft fruit, they eat the nutritious flesh around the seed and either discard the seed or swallow it whole. This helps spread the seeds of soft fruits and their parent plants encourage animals to eat them. When animals eat nuts, they crack the seed itself open and eat the embryo inside. This kills the seed and is the exact opposite of what the nut-bearing plant wants. To counteract this, some nut trees have developed mast reproduction. Mast reproduction works at the population scale with all trees in a population or region responding in unison to some environmental trigger. The type of trigger varies widely by species but all achieve the same end goal. When mast reproduction is triggered, all the trees in an area will produce a bumper crop of nuts. This unified seed production has several benefits: it improves the chances of cross-pollination in wind pollinated species, the individual plants can take full advantage of ideal growing conditions to maximize seed production, and most importantly the trees can overwhelm would-be seed eaters. This latter benefit falls within the predator saturation hypothesis and the strategy is ostensibly victory through attrition. By starving the seed eating animals of nuts on non-mast years, the plants can keep their predator’s populations relatively low. Then when the trees undergo mast reproduction, there just flat out aren’t enough squirrels, deer, mice, or turkeys to eat all the nuts before the next spring. Meaning a far higher proportion of seeds will survive to germinate than otherwise would have been possible.
American Beech can reach a considerable diameter and live for several centuries. However, few large Beech trees remain as they often grew on the most productive agricultural soils, which have long since been logged, and those that grew elsewhere were easily damaged by fire. Those large trees that do remain or those that have come up in the last century are invariably vandalized. Beech’s thin, smooth bark is seen by hikers and love-struck youths as a perfect canvas for carving. Carvings damage the thin layer of vascular cambium below the bark. Damage to this layer prevents that portion of the trunk from growing, causing the surrounding tissue to swell and callous in an attempt to heal the wound. On thin skinned trees like Beech, it can take years or even decades for these wounds to heal and even longer for callouses to disappear. A single carving is rarely a problem for a fully grown tree but trees on public parks or along hiking trails are often filleted to the point of infection. Each carving exposes the tree to infection and the wood of Beech is not particularly rot resistant. Meaning any carving may end up being the death nail for the tree.
