This week for Flora and Fauna Friday, we have one of our most iconic and largest butterflies: the Eastern Tiger Swallowtail (Papilio glaucus).
The Eastern Tiger Swallowtail is a large species of butterfly in the Swallowtail family found throughout the eastern United States and one of our eight species of Swallowtail in South Carolina. I believe it is tied for second place for the largest butterfly in the state with its cryptic cousin the Appalachian Swallowtail but squarely behind the first place Giant Swallowtail. Eastern Tiger Swallowtails are an unmistakable butterfly, except for when they’re not. Most Tiger Swallowtails are a rich yolk-yellow below and above that’s bordered and striped with strokes of charcoal black. Their hindwing fringes features a dash of chromatic diversity, with a splash of iridescent sky-blue and a few flecks of warm-orange. Male and females are quite similar but females tend to flaunt more substantial blue coloration. However, some female Tiger Swallowtails look radically different. Females can also appear as a dark-morph, which throws a wrench in the identification gears. Here in the Lowcountry, dark-morph female Tiger Swallowtails are not that uncommon and show up regularly in certain habitats. Dark-morphs can be quite obvious, showing faint stripes above and below through their graphite wings, or quite difficult, looking very similar to a Spicebush Swallowtail with a solid black body and almost entirely blue hindwings. The best way to identify a dark-morph female is to look for a large size, unmarked abdomen, faint stripes on the underside of the forewing, and a thin dark line running through the middle of the blue of the hindwings.
Eastern Tiger Swallowtails nectar on a wide variety of wildflowers and are a common sight almost anywhere in the Lowcountry. The reason for their abundance is in their host plants. Eastern Tiger Swallowtail caterpillars will host on a wide variety of hardwood tree species including: Black Cherry, Tulip Poplar, Sweet Bay, Ashes, and Willows. One of these tree species can be found in most any wooded habitat in the Lowcountry and so, so can Tiger Swallowtails. The caterpillar of the Eastern Tiger Swallowtail is large, cylindrical, wrinkly, and lime-green with a thin yellow collar and a comically caricatured eyespot, complete with an angry eyebrow. Caterpillars create a hidey-hole out of a leaf to rest in. They do this by weaving a carpet of silk across the surface of a leaf and, as the silk dries, it rolls the leaf up like a taco shell around them. Larger caterpillars leave their tortilla tunnel to feed but return to rest and digest.
This week for Flora and Fauna Friday is a lanky legume with a pigment pedigree, Carolina Indigo (Indigofera caroliniana).
Carolina Indigo is a small, airy shrub found on dry sandy ridges between the pines of savannas and along oak-hickory wood-lines. It often gets about chest high with wiry burgundy stems lined by small scarce leaves and covered with fine, sparse hair. The plants love bare sandy soil below dappled sunlight and so often find themselves at home in fire prone pine savannas. Much like Coralbean, Carolina Indigo dies back to its roots every winter only to reemerge the following spring. Plants bloom in June and July with slender spires of tiny peach-colored pea flowers. Seed pods are minuscule and contain only one or two seeds.
Carolina Indigo is one of three species of true Indigo that were cultivated for dye in the colonial United States. However unlike its tropical cousins, Guatemalan Indigo (I. suffruticosa) and True Indigo (I. tinctoria), Carolina Indigo was never a major cash crop. Indigo crops were grown for pigment that could be rendered from their leaves. Fresh leaves and stems were harvested, fermented in vats of water, strained, agitated, and mixed with lime from baked oyster shells to produce a deep blue dye that was then dried, cut, packaged, and sold. Indigo experienced only a brief period of profitability in South Carolina before the Revolutionary War. Guatemalan Indigo was believed to have been the species of choice on South Carolina plantations. Yet, Carolina Indigo saw some limited use as a dye early on in history as well as minor use for individual domestic dye production. Carolina Indigo never took hold for two reasons: the dye it produced was paler and it had low yield of dye per acre due to a biology that differed considerable from its imported cousins. Unlike the tropical Guatemalan Indigo which yielded dense leafy growth and grew feverishly until first frost shut it down, Carolina Indigo had adapted to the temperate climate and some of the harshest growing conditions South Carolina had to offer. This meant it grew slow, had fewer branches with less leaves, and spent more time building a robust root system to survive droughts and fires. Without any competitive commercial utility, Carolina Indigo quickly faded back to obscurity where it quietly grows along our roadsides and woodlots to this day.
This week for Flora and Fauna Friday we have a cobalt cousin of the Cardinal, the Blue Grosbeak (Passerina caerulea).
Along the ditch within the field your train of thought derails on a curt, crisp “Tink” spit with force to split the brush and mark upon your attention. The statement receives an encore and several more as you blindly stare into the reeds and weeds for the source of the interruption. With a crane of your neck and a cock of your ear you shuffle closer. Your haphazard trespass is discovered to be unwelcomed as a dazzling whirl of cobalt rockets forth with a flutter of feathers and another, sharper, single-syllable, “Tink!” The indigo UFO skims across the shrubs to settle along a thicket and locks with your gaze before tumbling down within. Quite the common way to greet a Blue Grosbeak.
Blue Grosbeaks are a medium-sized songbird and the largest of our three Bunting species. Like its close cousins the Painted Bunting and Indigo Bunting, and it’s slightly more distant cousin the Northern Cardinal, the Blue Grosbeak is also an inarguably stunning bird to behold. Male Blue Grosbeaks are dyed a deep lazuli blue throughout that’s accented by two chestnut wing bars and fringed with jet-black flight feathers and mask. Females are not so boldly colored but still flaunt a handsome cloak of cinnamon and umber. Both sexes have a short tail, long body, and a heavy triangular bill. Grosbeaks are primarily seed-eaters but, like most songbirds, will gladly gobble up insects when given the opportunity. Grosbeaks prefer to inhabit scrublands, thickets, causeways, stream banks, and field edges and are most fond of overgrown drainage ditches in our area. Here they nest, rest, and forage. Blue Grosbeaks are more often heard than seen, spitting sharp one-note “Tink” calls at anything that comes too close to their abodes. When they are seen, it’s often briefly atop a bush or limb before darting back into the shadows of a shrub. The best time to view Blue Grosbeaks is spring when males stake their territory and sing its defenses.
This week for Flora and Fauna Friday we have a native fruit tree that’s scattered around the island just as it scatters its fruit below it, Black Cherry (Prunus serotina).
Black Cherry is a member of the stone fruit genus, which includes Cherries, Peaches, Plums, Apricots, and Almonds. It’s found throughout the Eastern United States (and is even an invasive species in some parts Europe). Black Cherry loves sunny fields and well-drained soils and can put on a lot of height in a short amount of time. However, it will grow alright in most habitats and can tolerate some shade. The best way to recognize Black Cherry is by its finely flaky, silvery-black bark. That bark envelopes some of the finest wood in the Southeast. The deep orange timber of Black Cherry has long been prized for its woodworking merits and is often used for building high-end cabinetry and furniture. Another easy way to tell a Black Cherry is by the leaf. But it’s not the simple elliptical shape, glossy emerald-green color, alternate arrangement, or fine marginal serrations that give it away, it’s the scent. Crush a Black Cherry leaf and give it a whiff and you’ll be greeted with the unmistakable scent of cyanide. A scent most recognizable from fresh Almonds or, for us gardeners, from Greenhouse Millipedes. This scent alone is not harmful to us but that cyanide is indeed there for poisonous purposes. Black Cherry’s tissues are stuffed with cyanide to deter herbivores and insects from feeding on it. However some species, like the Eastern Tent Caterpillars I’ve covered before and the Eastern Tiger Swallowtail, have learned to ignore this cyanide seasoning. Follow the branches down in spring and you’ll likely be greeted by the flowers of Black Cherry. These blooms are small and white but conglomerated into a large hanging bottlebrush that attracts many a bee. These flowers of course give way to a fruit in due time. In early summer the fruits begin to ripen and drop en masse. Eat fruit is only a quarter to third of an inch in size but boy are there a lot of them. These cherries are spherical and so deep a red as to be black. These are a favorite food of songbirds, Turkeys, Quail, and Raccoons. They’re also edible to humans as well but they’re rather bitter and better cooked and sweetened than raw. The pits are not edible, they’re extra cyanide-y FYI.
This week for Flora and Fauna Friday we have a locally named but widespread critter, the Carolina Locust (Dissosteira carolina).
The Carolina Locust is found throughout the continental United States and even reaches into Mexico and Canada. Despite the biblical connotations, today’s Locust is not a swarming species nor is it known to be a regular agricultural pest. The Carolina Locust a good-sized, 1.5 to 2 inch, grasshopper. The species emerges from the ground as a nymph each June. Those nymphs hop themselves along, feeding on grasses and forbs, until they can undergo their last molt and finally spread their wings as full-fledged Locusts. The Carolina Locust is a cryptically colored insect whose color pattern often camouflages them perfectly against their environment. That environment is usually roads. They like dry, dusty habitats and are partial to hanging out on dirt and gravel roads where they seamlessly blend into their surroundings. They come in many shades of grays and browns but, whatever their neutral of choice, they’re always thoroughly speckled and subtly variegated so as to be almost imperceptible when standing still. However, when they’re in motion, they’re hard to ignore. When Carolina Locusts take flight, they reveal an oversized set of black wings fringed in ivory white. Their deep wing beats and slow flight gives them the impression of a butterfly at first glance.
The week for Flora and Fauna Friday it’s another often overlooked weed with some surprising culinary character, Dune Groundcherry (Physalis walteri).
Dune Groundcherry, AKA Walter’s Groundcherry, is one of several Groundcherries found in our state. However, of the three found on Edisto, it’s the most common species you’ll encounter. It’s a perennial that grows heartily on sandy soils in full sun. It can often find a foothold even amidst grasses and the weedier forbs of fields and wood lines. The foliage is bluish-green with a silvery hue from the fine coat of hair which coats its upward cupping leaves. The plant itself is fairly compact and is usually only a foot or so in height. The flower is a small weeping funnel of pastel-yellow with a center inlaid with ebony. Once pollinated, a pendulous fruit will emerge; a paper lantern, vertically ribbed, dangling by a sinewy string. As the fruit grows and matures, it eventually yellows and dries. As it dries, its skin flakes away to reveal an intricate lattice of ashy veins that cage a golden morsel at its core. That orange-yellow sphere is the real fruit; the cherry atop the ground.
Groundcherries go by another name, Husk Tomatoes. It’s a name that’s pretty on the nose. Groundcherries are actually close relatives of the tomato and so their similarities run deep. Just one look at the hanging yellow flowers, silver-haired leaves, forked branches, and its smooth-skinned, spherical, orange berries will illustrate what I mean. In fact, the common Tomatillo (Physalis philadelphica) is a member of the Groundcherry genus too. Just like its culinary cousins, the fruits of Dune Groundcherry are edible as well! However, they’re poisonous when green, so it’s best to let them vine ripen before peeling away the husk and popping them in your mouth. I’ve been told they’re sweet with quite a fruity taste but, as they’re a favorite of wildlife, I’ve yet to get a chance to try one.
This week for Flora and Fauna Friday we have a secretive, jewel encrusted reptile on display; except it’s not the long and rattling one, it’s the round and bony one. This week we’re gazing upon the Diamondback Terrapin (Malaclemys terrapin).
Between the cast of a shrimp net a chaotic bobbing on the upstream surface makes itself known. A hypnotic shell of swirling circles within circles aggravates your eye. It begs attention to a turtle. A turtle with pearly-white skin of an almost luminescent alien glow radiates between pluff mud polka dots and tiger stripes. A wide grin through thick peachy-lips of hardened bone smiles back at you. It scuttles along the bank beside your feet before careening down an inlet and out of site. Clutching your net you stand dazed with awe. A wondrous sight few see but none forget. Today’s turtle is extra special. Not only is it unreal in its beauty but it’s become adapted to life in the briny drink entirely separate from Sea Turtles.
The Diamondback Terrapin is a typical size for a Pond Turtle, usually a hand span or less in length. Females are far larger with a more robust head. A Terrapin’s shell is flat and furrowed along concentric circles within the scutes. Rings of gray, tan, and black alternating like a hypnotist’s wheel. Their skin is a milky-white with a wash of sky-blue. It’s flecked with uncountable black speckles and splotches from webbed toe-tip to their broad smirking mouth. That grin is a beak made of peachy-yellow bone. Terrapins use that beak for meal prep. They’re a carnivorous species with a preference for shellfish. A female’s over-sized chompers are perfect for crushing periwinkles, fiddler crabs, mummichogs, shrimp, mussels, fingers, and grasshoppers. Males prefer the softer options in the salt marsh.
Diamondback Terrapins have salt glands that they use to expel excess salt from their body. This allows them to drink and live in saltwater without dehydrating. They’re far more efficient than Alligators at this but not as adept as Sea Turtles. So Terrapins stick to tidal ecosystems where the salinity is lower. Here in our tidal creeks they spend their lives crunching crabs and flailing about oyster reefs mostly hidden from the view of humans beneath the sediment saturated saltwater. However, in May females come ashore to lay their eggs. Your best chance to see a Terrapin is as she makes her way onto a nearby causeway or hammock island to nest.
Diamondback Terrapins were historically harvested to make turtle soup. Centuries of harvests have taken their toll on our turtle. Turtle soup has fallen out of favor but commercial crabbing became a new threat. Terrapins like to eat crustaceans and crab traps are designed to funnel critters in but not out. Thus, Terrapins often get caught in crab traps and drown. They received some government protections against collection in recent decades but their populations are still critically low. If you crab, please equip your traps with Bycatch Reduction Devices. They keep big Terrapins out and make it easier for small turtles to escape.
This week for Flora and Fauna Friday we have a common wildflower of spring, Cut-leaf Evening-Primrose (Oenothera laciniata).
Cut-leaf Evening-Primrose is a common herbaceous annual found across Edisto Island. Its leaves are deeply lobed and its stem gnarled and drooping. Stems are usually reddish and finely haired. It’s found most often in sun on sandy soils but will grow in most open habitat where soil is bare. The flowers are middling in size with four heart-shaped petals a pastel-yellow. As the flowers age and fade they turn an orange that sinks to pink. The petals then curl in and abreast a new bloom is ushered forth to take its place. This species can be quite prolific and even becomes a groundcover in the right conditions. The fruits are finger shaped and dry to shed many small seeds. This species belongs to a diverse genus with many varied species.
The Cut-leaf Evening-Primrose is small and rather inconspicuous compared to its cogenerates. Species in the same genus include the hot pink and large-flowered Showy Evening-Primrose (O. speciosa), the man-height Common Evening-Primrose (O. biennis), the dune blooming Beach Evening-Primrose (O. drummondii), and the feathery formed, thread petalled Southern Beeblossum (O. simulans). While these species may be more impressive aesthetically, physically, or ecologically, none fill the same niche as our little Cut-leaf Evening-Primrose. It’s small, ragged, and weedy but Cut-leaf Evening-Primrose is our most common member of the Evening-Primroses. Although so slight, it provides much needed pollen and nectar to our spring bees where the others cannot reach. A humble and diligent flower in every way.
This week for Flora and Fauna Friday, we have a pair of indistinguishable butterflies. A set of Satyrs so subtly distinct it took a genetic study to discover the differences some 220 years after first described. This week we’re talking about one of my pet projects, the Carolina Satyr (Hermeuptychia sosybius) and the Intricate Satyr (Hermeuptychia intricata).
I am not going to get technical on the subject today but instead speak about this species complex as an example in regards to the modern scientific landscape of taxonomy and species discovery. If you want the technical details for some reason, I have a publication on the subject in the Journal of the Lepidopterists’ Society you can read. [Austin, 2018. 72(4):307-313.]
The Carolina Satyr was first described at the end of the 1700s. It’s an incredibly common species of butterfly that eats grass, drinks tree sap, and is found in forests throughout the southeastern United States. There’s nary a woodlot in South Carolina that this insect doesn’t call home. Edisto Island is no exception. What’s incredible about the Carolina Satyr is that it turned out to be two species across nearly half its range. In 2014 a team of researchers performing a phylogenetic study of the genus in North America made the find. What the researchers found was a new species of Satyr in the Southeast US, the Intricate Satyr. Phylogenetics is a field of biology that examines the genome of an organism and compares it to others to determine how they are related. This can reveal when species first appeared, where their ancestors originated, and whether one descended from another. Often, the results lead to reorganization of a genus or creation of a new taxon. Sometimes, like in the case of our Satyrs, they find hidden species. Often these new species are contentious. They’re impossible to tell apart, reproductively indiscrete, or possibly just subspecies. Personally, I’m in the camp of physiological reproductive isolation is a prerequisite for designation of a discrete species.
What’s interesting about the Intricate Satyr is that it is more ancient than the Carolina Satyr and has a narrower range completely within that of the Carolina Satyr. Upon closer examination of specimens, the researchers revealed that it was indeed a discrete and separate species, different not only in genome but physically distinct and incapable of hybridization. A true-blue species by any definition of the word, undiscovered in the eastern United States for over 200 years. Where I come into this story is 2016 when I began researching field identification techniques and the ecology of the Intricate Satyr. The two species are incredibly similar but still distinct. There was not yet robust documentation of the morphology of the new species. At the end of 2018, I published my work detailing the differences I documented between the ecologies of the species in South Carolina and how to successfully identify between the two in the field.
This example of the subtle Satyrs highlights how scientific discovery in the field of biology has changed in North America over the centuries. Gone are yesterdays; the days of hiking through the wilds of the frontier collecting bags upon bags of specimens of new, foreign life forms. However, the days of discovery have never left. Here today are the days of sitting down in a lab and looking really hard at what has already been done and piecing together the puzzle collected by the generations before, one bug at a time, to produce an ever more detailed and intricate view of the world around us. No one noticed this species for two centuries but there were morphological differences that could have distinguished them all this time. Just think what else is out there under our nose, waiting for someone to look close enough to notice.
This Week for Flora and Fauna Friday we have the crown jewel of the swamp, Virginia Iris (Iris virginica).
Through the columns of Gums and over the foundation of muck a twinkle of violet shifts under the weight of a Darner. Dangling over a palisade of emerald blades a crown of color beckons. Swallowtails and skippers flutter and flee from its fringes amidst the darting strikes of darners and skimmers. Behind the bulwark flies the standards of its colorful comrades, rising above their verdant outpost. An encampment of Virginia Iris in the barren mire of the swamp.
Virginia Iris is a large species of wetland wildflower found throughout our coastal plain. It grows through its roots into spreading clumps, shin-deep in water on the fringes of permanent, shady wetlands. It’s large, flat grassy-leaves reach waist height as they arch upward and outward from the water in overlapping fans. In April they send up stalks to bear their flowers. Palm-sized, six-petalled, multi-colored, double-decker flowers primed in white, painted in violet, accented with saffron, and inlaid with veins of crimson. These flowers act as beacons not only for the curious naturalist but for the wandering insect. Pollinators, still groggy and ravenous from the prior season’s sleep, flock from across the swamp to this chromatic café, some sipping their first nectar for the year.
