This week for Flora and Fauna Friday, we’ll admire the scarlet spire of stream and mire, Cardinal Flower (Lobelia cardinalis).
Cardinal Flower is one of about eleven species of Lobelia native to South Carolina and is the widest ranging Lobelia in the United States. Of those eleven, it is the easiest to identify by a mile! Most Lobelias grow to about two feet high, have a single thin stem, have but a few small leaves, and produce small blue or purple flowers, with many species having pale-purple flowers. Cardinal Flower on the other hand towers up to four feet tall, has abundant long and fairly broad leaves, a lone stout stem, and large, brilliant scarlet-red tubular flowers. There’s nothing else like it!
The primary pollinator for Cardinal Flower is the Ruby-throated Hummingbird, which their flower is specially shaped to accommodate. Brilliant red flowers are like neon lights for hummingbirds, and their tubular shape ensures only the largest of pollinators can reach the abundant pool of sugary nectar nestled deep within. Each flower has five narrow petals, with three pointing downward and the other two pointing to either side. It’s a shape that forces pollinators to approach from above and makes the flower hard to land on. That’s a difficult task for a bee or wasp, but child’s play for a Hummingbird. Standing at the top of this flower is a pillar that’s tipped with its anthers and stigma, one appearing before the other, respectively. These are perfectly positioned to tickle the back of a hummingbirds head when it buries its bill in the bloom to gulp down nectar. As that buzzing bird bobs between blossoms and systematically sips from stems along the side of a stream, it moves pollen around with ease and efficiency between the isolated patches of Cardinal Flower. This ensures cross-pollination for that local Cardinal Flower population and a more diverse gene pool for its descendants. Apart from Hummingbirds, assorted sphinx moths and some longer tongued butterflies, like swallowtails, Cloudless Sulphurs, and Clouded Skippers, will also frequently visit Cardinal Flowers to sneak a sip of nectar.
Here in South Carolina, Cardinal Flower is most abundant in the Appalachian Foothills down through the Piedmont to the Fall Line. Although rarely found on the Sea Islands, it can still be found here and there across the wider Lowcountry. It grows best in the wild along flowing freshwater streams, creeks, and rivers, especially on sunny stream banks and bars. You don’t normally find it in stagnant swamps or sloughs, nor isolated dug ponds, but it will line the shores of lakes and ponds created by impounding the natural flow of streams. It can also do well when planted in a wetland garden or peppered into the periphery of a freshwater pond or canal.
This week for Flora and Fauna Friday, we’re getting wise to the ways of the butterfly master of disguise, the Spicebush Swallowtail (Papilio troilus).
The Spicebush Swallowtail can be found across the Carolinas and much of the Eastern United States. It flies from March through October. Although one of our largest butterflies, it’s about mid-sized for our State’s eight Swallowtails species. They can also be tricky to tell apart from our other dark Swallowtail species. Spicebush Swallowtails are mainly black across their body and wings. Above they have a single row of pastel-yellow spots spanning the border of all four wings, a pair of small orange wing spots right behind the abdomen, and a blue patch covering most of the hindwings. In males this blue patch is larger and of a more powder-blue. In females it’s less expansive but a richer sky-blue. Below both sexes appear much the same, with mostly black on the forewing and the hindwing bearing two concentric arches of orange spots sandwiching a band of blue. Unique to the Spicebush Swallowtail, on the inner arch of spots, there is a gap between the fourth and fifth spot that is punctuated by a “rocket” of blue shooting through towards the body.
The wing patterns and colors of the Spicebush Swallowtail deliberately mimic another butterfly, the Pipevine Swallowtail (Battus philenor). The Pipevine Swallowtail looks much the same, but with deeper blue, darker black, and less yellow. The Pipevine Swallowtail hosts its caterpillars on, predictably, Pipevines (Aristolochia spp.). This is a clade of plants containing toxic aristolochic acid, which causes severe kidney damage in vertebrates and wards off most insects. Pipevine Swallowtail caterpillars are highly resistant to this toxin and even concentrate it into their bodies, to provide them a chemical defense against predators. This toxicity persists to adulthood and, as a butterfly, their striking blue and black colors serve as a warning to any would-be predators. This is called aposematic coloration. Spicebush Swallowtails, however, are not toxic. Yet they look much like their poisonous Pipevine parallel. This is called Batesian Mimicry, where a harmless animal pretends to be a different dangerous one for protection. The Spicebush Swallowtail also flutters its wings incessantly when drinking nectar, a characteristic shared with the Pipevine to maximize visibility.
Spicebush Swallowtails host on a number of deciduous shrubs in the laurel family, Lauraceae, including Northern Spicebush (Lindera benzoin), Sassafras (Sassafras albidum), Sweetbay Magnolia (Magnolia virginiana). Their eggs are laid singly and their caterpillars are leaf folders. They spin silk from one edge of a leaf to the other. That silk then dries, contracts, and starts to bend the leaf upward. The caterpillar then bridges the gap across the top of the leaf, finishing the lengthwise fold and completing their new “leaf taco” home. They can then eat inward from the edge of this folded foliage while remaining hidden and secure. When young, Spicebush Swallowtail caterpillars are a mottled greenish-brown above and white below, to camouflage themselves as bird droppings. But once they grow into their final instars, they take on a solid emerald-green color and, just before pupating, turn a vibrant yellow-orange.
Each phase of the caterpillar’s development sports a pair of large black and yellow eyespots behind its head and a smaller set of yellow eyespots behind those. When disturbed, Spicebush Swallowtail caterpillars will lift their head slightly and swell the front of their abdomen between their eyespots, emphasizing those eyespots and giving their body an arrowhead shape. When harassed, they will unfurl a forked, foul-smelling orange osmeterium from just behind their head and will attempt to rub its stink on their aggressor. This whole display seems odd in a vacuum but is actually a brilliant form of mimicry. When in a defense posture, a green-phase Spicebush Swallowtail caterpillar is a dead ringer for a Rough Green Snake’s head, down to the right eye color and a correctly colored forked tongue! If you’re a songbird or a lizard swooping in for an easy meal and come face to face with the facade of a snake, you’re going to panic and skedaddle, no doubt.
Although the Spicebush Swallowtail’s caterpillar is quite distinct, its larva is very similar in appearance to the Palamedes Swallowtail (Papilio palamedes). The two differ in appearance subtly, with the silvery “eyebrow” of the Palamedes Swallowtail caterpillar sitting on the edge of its yellow eye-ring, while that brow is fully enveloped for the Spicebush Swallowtail, plus some other minute deviations. However, the two differ boldly in behavior. Palamedes Swallowtail caterpillars rest boldly, in fully display, upon the upper surface of a leaf just daring a bird to test their mettle. Conversely, Spicebush Swallowtail caterpillars cower and hide, quite wisely, within their leafy security blanket.
The Swallowtails, family Papilionidae, get their common name from the pointed projection trailing from the bottom edge of both their hindwings. These “tails” are reminiscent of the long, forked tails of Barn Swallows, which lent the family its name. Yet rather than being used for aerial acrobatics, butterfly tails are used for distraction and diversion. These tails are like visual chaff to any attacking bird, dragonfly, or spider. As the ambush commences, the predator comes in for the kill with a mere split-second to make a decision regarding a face full of fluttering wings. In that instant, these tails present an obvious target. The dangling tails resemble an insect’s antennae, where the head is, the kill shot. But the attacker instead only ends up with a mouthful dusty, papery wing. These tails, and the trailing edge of the wings they attach to, are quite fragile and break off easily, to ensure a clean escape if grabbed. Letting the butterfly live to flutter by another day.
This week for Flora and Fauna Friday, we’re picking up hitchhikers from the Tick-trefoils (Desmodium spp.).
Here is South Carolina we have roughly eighteen species of Tick-trefoil found around the state. All of them share several traits that make them readily identifiable to genus. Yet to get one down to species, I hope you enjoy dichotomous keys! I won’t leave y’all entirely high and dry today though. There are three Tick-trefoil species I encounter pretty often around the Edisto area, which are relatively easy to identify and worth highlighting: Panicled Tick-trefoil (Desmodium paniculatum), Sand Tick-trefoil (Desmodium lineatum), and Twisted Tick-trefoil (Desmodium tortuosum).
Overall, Tick-Trefoils are small herbaceous legumes that grow up to around knee height. They typically thrive on drier soils. They have trifoliate compound leaves and small, quarter-inch hot-pink pea-flowers. Their seedpods are long, flat, fuzzy, and jointed. Like a Toblerone viewed from the side, just hairier. The shape and profile of these seedpods varies between Tick-trefoil species and can be quite useful in telling similar looking species apart.
Panicled Tick-Trefoil is one of the most widespread Tick-trefoils in the Eastern United States, is found across South Carolina, and in my mind is the proto-typical species I imagine for this genus. It is perennial and grows abundantly in pine savannas, forest openings, roadsides, and old fields. It reaches to between knee and waist height and has thin, wiry stems. Its leaflets are fairly narrow, often pointed, are a deep green above sometimes with a faint streak of pale variegation down the midvein, and have a slightly cupped, recurved margin. It produces a panicled flower stalk bearing roughly a half-dozen flowers at once. These flowers are a quarter-inch wide, hot-pink with two yellow spots towards the center, and have that typical pea-flower shape of most legumes. Its seedpods are normally three seeds long, each with a right triangle in shape.
Sand Tick-Trefoil is mainly found in the Coastal Plain and Sandhills of South Carolina in dry pine savannas and coastal sand ridges. It grows as a prostrate groundcover, making it more resilient to fire, mowing, and herbivore browse. It has rounded leaflets, each about the size of your thumbnail, and of an emerald-green color with sunken veins. It bears upright flower stalks, reaching around a foot high, capped with a panicle of quarter-inch hot-pink pea-flowers, looking much like the inflorescence of Panicled Tick-Trefoil. Its seedpods are three to four seeds long and each rounded in shape.
Twisted Tick-Trefoil is found mostly below the Fall Line in South Carolina, mainly in disturbed areas, fields, and along roadsides. It’s not certain to botanists whether it’s native to Florida and the wider Southeast, or if it was a stowaway from Mesoamerica. Regardless, it is here now, is abundant throughout the state, and gets around as a common component in many food plot seed mixes. Twisted Tick-Trefoil grows waist to head high in good conditions on a fairly heavy stem showing prominent nodes and covered in fine hairs. It tends to be an annual but will sometimes persist as a shot-lived perennial. It is quite leafy for a Tick-trefoil and has large, velvety, diamond-shaped leaflets that sometimes show small purplish spots. It will flower at the top of its leading stems with a tight knit panicle of (say it with me) quarter-inch hot-pink pea-flowers. These flowers mature into seedpods with a distinct wavy, twisted shape. Each section is almost spherical and six to seven seeds long.
Tick-trefoils get their common name from their seedpods. These seedpods fracture at their joints when mature and the short, stiff hairs covering them function like Velcro. They’ll adhere to any passing mammal’s fur that brushes against them, hitchhiking far afield. If you’ve ever trekked through a pine savanna in fall, or had a dog that can’t help but follow its nose, you know what these seedpods look like and how well they can stick! This is an effective seed dispersal strategy as it hijacks the motility of mammals to move around its offspring, allowing their seeds to be larger without the parent plant needing to invest in a calorie rich fruit bribe. Yet, Tick-trefoils might actually be doing both.
As a protein rich legume, the leaves of Tick-trefoils are some of the most highly desirable forage to herbivores, especially White-tailed Deer. Deer think with their stomachs, and their gut instinct is to eat every Tick-trefoils they encounter! This might seem like a death sentence for our little legume, but it might actually be part of their master plan. Tick-trefoils don’t have any special herbivory defenses against vertebrates, no prickles, spines, nor nauseating toxins. They just leave their guard down and tolerate the consequences. They bear few leaves overall, and will regenerate foliage quickly if browsed. But, that also means they are training the local deer population to go out of their way to visit them regularly. What a perfect ploy to saddle these four-legged interlopers with their triangular seeds. Rather than investing energy in coating their seeds in a delectable fruit or defending their foliage with point and poison, the Tick-Trefoil simply saves those resources to regrow its leaves on a whim. A character trait that also confers great resilience to fire.
SC Artists have been painting at the Store Creek Corner on Edisto Island for months, creating artwork depicting the beauty of Edisto with the goal of “protecting their Muse.”
In 2024, Preserving a Picturesque America (PAPA) had a celebrated exhibition in Charleston with modern interpretations of artwork created in the 1800s. To follow up on its success, an exciting show in Edisto will feature NEW locations also considered picturesque and in need of preservation. It is a continuation of PAPA’s mission to create collectible artwork that helps bring awareness and protection for significant places in South Carolina.
Exhibit organizer and 3rd-generation artist Louise Britton lives on Edisto Island land her family has owned since 1740. “My siblings and I chose to protect the family land, which is not far from Store Creek Corner, from development with a conservation easement held by Edisto Island Open Land Trust.”
The original founders of EIOLT were six local property owners who were quickly joined by additional Edisto residents, large and small landholders, and second-home owners. All were united in a common goal to preserve Edisto, the legacy of their property and their island as a whole. PAPA, with a nationwide focus, strives to shift public perspective toward the importance of the natural landscape through art experiences and opportunities to reconnect with nature, and uses those opportunities to raise funding that will facilitate the protection and preservation of Picturesque America sites across the country. PAPA is also inspired to assist in the preservation of new picturesque sites not originally represented in the Picturesque America collection. With these goals in sight, EIOLT and PAPA make a perfect pairing in their shared goal to preserve the natural beauty and historic elements of Edisto Island.
“So many caring artists have shown up to do their part by creating amazing works that celebrate the places that inspire them. Now it is important that the people who love the beauty of the Lowcountry come out and purchase this artwork to support its protection.” -Scott Varn, Executive Director of PAPA
EXHIBITION: Preserving Edisto Through the Power of the Arts
ORGANIZATIONS: Preserving A Picturesque America; Edisto Island Open Land Trust
LOCATION: Bailey House, 8083 Point of Pines Road, Edisto Island, SC
OPENING RECEPTION: Friday, Aug 21, 2026, 4-7 p.m.
DATES: Friday, Aug 21st through Saturday, Aug 29th 2026
HOURS: 10 a.m. to 5 p.m. daily
This week for Flora and Fauna Friday, we’re trying to catch a glimpse of the booming bullbat, the Common Nighthawk (Chordeiles minor).
The Common Nighthawk can be found across most of the United States in summer, including all of South Carolina. It’s one of three species of Nightjars found in the Southeast, along with the Chuck-will’s-widow (Antrostomus carolinensis) and Eastern Whip-poor-will (Antrostomus vociferus). Nightjars are an odd clade of birds and our three local members all share a few common traits. They sport long wings, cryptic brown plumage, big eyes, a small beak, and a huge mouth. Our Common Nighthawk ticks all those boxes and stands out with its larger frame more streamlined pointed wings, with a white band near each wingtip, as well as a white crescent under its chin.
The Common Nighthawk, and our other two Nightjars, are insectivores. They hunt by hawking, snatching insects from the air while flying on the wing. Their streamlined shape lets them be fast fliers and their large eyes give them impressive vision during their preferred hunting hours at dawn and dusk. Their secret weapon, however, is their gaping maw. Despite having a tiny little beak, a Common Nighthawk can open its mouth about as wide as its whole head! They fly head first, mouth agape, right at prey, scooping it up in their mouth like a butterfly net. Their acrobatic twilight twirlings gave them the common name of “bullbat”, in ye olden parlance that means the “big bat” or “boss bat”.
Common Nighthawks come to the United States to nest each summer and can be found in open habitats across the Country. Here in the Lowcountry I see them most often near rice fields, beaches, big clearcuts, and expansive savannas. They’re a scarce bird here and don’t often make an appearance. Common Nighthawks, alongside our other Nightjars, are ground nesters. They lay usually just two camouflaged eggs in a shallow depression on the ground and prefer to nest on gravel or coarse sand, but will pick the best substrate available to them to nest. Often times they end up nesting on gravel roofs, parking lots, or infrequently traveled road. Once those eggs hatch, their young’uns will be force-fed as many bugs as they can gulp down and should be ready to fly within the month. When a mother Nighthawk is incubating her eggs or chicks, she’ll do her best to remain motionless and use her camouflage to hid from sight. But if stumbled upon too close, she’ll burst from the nest, drop a few yards away, flail her wings, and make a ruckus in an attempt to distract any would be predators away from the nest by playing like she’s injured and can’t fly. She’ll then lead whatever bothered her along a ways before flying off and circling back to her nest.
Usually you hear a Common Nighthawk long before you see one. The call of the Common Nighthawk is a loud, nasally, vibrating “Beent!” Hollered forth on the air waves every few seconds. But males have another trick up their sleeve. The Common Nighthawk is also renown for their booming courtship call, which is a deep, loud industrial ruckus sounding somewhere between a bullfrog and a 10L jake-brake. Males make this sound to court females during breeding season. They accomplish this cacophony by diving straight down into a freefall. They then shift the feathers of their wingtips just so, to change their aerodynamics to vibrate violently in the turbulent air.
This week for Flora and Fauna Friday we’re going snow-blind staring at the radiant blooms of Beach Morning-Glory (Ipomoea imperati).
Beach Morning-Glory can be found sprawled out on beaches nearly the world over, including up and down the South Carolina coastline. It grows upon the beach dunes with low, running vines that cling to the ever-shifting sand until they become entombed beneath its grains. The leaves of Beach Morning-Glory are small, evergreen, with rounded margins and inconsistent lobes, and have a thick leathery texture. All these leaf traits are features to help this plant retain water and resist the harsh unyielding light of the sun. Beach Morning-Glory blooms beginning in June and carries forth new blossoms through to fall. Sometimes it will even bloom year-round! Each flower is up to three inches in breadth, with a fused bugle of pearl-white petals that concentrate around a lemon-yellow center. These flowers provide needed nectar and pollen for seaside pollinators, especially native bees, during the dog days of summer.
As a low perennial vine, Beach Morning-Glory plays an important roll among the cadre of plants that call our Lowcountry beach-dune ecosystem home. It’s on the forefront of the beachfront, working alongside Largeleaf Pennywort to permeate and stabilize the sands at the feet of the dunes. Beach Morning-Glory serves as both a net and miniature silt fence, which buys the time for the Sea Oats and Coastal Panic Grass to creep in and start their work building up new dunes. So the next time you’re open combing Edisto Beach, take a second to appreciate the hard work and long hours in the beating sun that Beach Morning-Glory, and all our other native dune plants, put in to keep our beaches healthy.
This week for Flora and Fauna Friday we’re dodging the shadowy approach of the buzzing bloodsucker of the bottomlands, the Black Horse Fly (Tabanus atratus).
The Black Horse Fly is a hard bug to miss, especially when one comes buzzing out the brush aimed at your back like a black heat-seeking missile. It’s our easiest biting fly to identify by a wide margin. Measuring in at a bit over an inch in length, the Black Horse Fly is a contender for our largest biting insect as well as one of our largest Flies, order Diptera, found in the Lowcountry. This fly is stoutly built, torpedo-shaped, and solid black from antennae to abdomen tip. Males and females look nearly the same, but males have larger compound eyes that press against each other, leaving nothing but a seam between running down their forehead.
The Black Horse Fly can be found throughout all the Eastern United States and all across South Carolina. Males are pollinators that subsist on flower nectar and plant sap. Females are ectoparasites that bite and drink blood from large mammals. This includes deer, bear, bison, and elk, as well as more domestic animals like hogs, cows, and horses. They rarely bite humans, and generally get gone if shooed away. Often times Horse Flies will chase slow moving vehicles and land on them, being attracted to the large, hot, carbon dioxide leaking thing moving through their airspace. They’ll stay perched on that car, boat, or side-by-side until they realize there’s no blood to be sucked. Female Black Horse Flies, and in general all female biting flies, use this blood meal to garner the nutrients they need to lay their eggs. Females lay their eggs in conical masses on the underside of a grass blade or leaf overhanging a pond, marsh, or other permanent wetland. Those eggs eventually hatch and the larvae plop down into the wetland below. Under that murky water, a white and gray banded maggot will feed on aquatic insects over the next two years, eventually growing to nearly two-inches in length, before it crawls on land and pupates in the soil. Adult Black Horse Flies emerge near the start of summer and fly until September, with females being longer lived than males.
To talk on Tabanid taxonomy a tad bit, a distinction needs to be made between the three main tribes within the overarching Horse Fly family, Tabanidae. In one subfamily you have the Deer Flies (most are Chrysops spp.). In another subfamily are both the Yellow Flies (Tribe Diachlorini) and the Horse Flies (Tribe Tabanini, most are Tabanus spp.). Deer Flies (Chrysops spp.) are all small, measuring in at roughly three-eighths-of-an-inch long. They tend to be striped black and yellow on the body and will bite just about anything that moves, be that a deer, dog, jogger, or car. There are over a dozen species of Deer Flies in South Carolina. The Yellow Flies are small in total number of species but quite varied in appearance. Most are white, green, or yellow in color. The eponymous Yellow Fly (Diachlorus ferrugatus) is its most infamous member. The Yellow Fly looks much like a Deer Fly, but is a solid golden-yellow in color, and bite just that little bit harder. The Horse Flies are the largest group and range in size from half-an-inch up to just over an inch in length. There are well over seventy-five species of Horse Fly (Tabanus sp.) in the United States and over twenty species found here in South Carolina, including both the insatiable Greenhead Fly (Tabanus nigrovittatus) and the rather satiable Black Horse Fly.
This week for Flora and Fauna Friday, we find a variegated vine that twines along shadowed wood lines, Yellow Passionflower (Passiflora lutea).
Yellow Passionflower is found throughout the Southeast and all of South Carolina. It’s the more subdued and subtle sibling to the bold Purple Passionflower (P. incarnata) that blazes its brilliance in the sun baked pastures, prairies, and pineywoods around the State. Yellow Passionflower instead offers an air of restrained elegance within the verdant shadows of forests across the region. Yellow Passionflower is most often encountered on roadsides, trails, hedgerows, and river bluffs where there is ample shade from the sun rays. It’s a thin and wiry vine that anchors itself with tendrils and climbs into and over low shrubs. Yellow Passionflower grows up to a little over head height and hangs a loose, scattered collection of leaves out in the air to intercept wayward rays of sunlight. Its leaves are a soft, deep, bluish green, occasionally with blotches of silvery wash variegating its veins. Each leaf is trilobed and can vary in shape from nearly round, to pointed and stringy, like the three-toed footprint of a bird. In early summer, Yellow Passionflower begins to bloom, bearing a roughly one-inch, pastel yellow-green blossom. Although small and monochrome in color, it is a flower no less complex and wondrous than its purplish kin.
Five petals support a stage of some fifty radiating coronal filaments. At their inward convergence stands a towering ovary crowned with five hanging anthers and five dangling stigmas. Like some strange alien streetlight or radio antennae, it radiates signals into the surrounding landscape to draw in pollinators. Pollinating insects land on the elongated filaments of the flower and crawl to the base to grab a sip of nectar. Those hanging anthers dust their backs with pollen as they pass beneath and the dangling stigmas take samples from others for cross pollination. Passionflowers are most attractive to bees, but well used by myriad other pollinators. These flowers, once pollinated, will mature into a miniscule blue-black berry, to be gobbled up by birds and carried further on down the road. The foliage of Yellow Passionflower also hosts the caterpillars of several butterflies, including the Variegated Fritillary, Gulf Fritillary, and is the preferred host plant for the Zebra Longwing here in the South Carolina Lowcountry.
This week for Flora and Fauna Friday we’re watching the whirlings of a dashing little dragonfly, the Blue Dasher (Pachydiplax longipennis).
The Blue Dasher is a small dragonfly found across much of the continental United States, including all of South Carolina. It’s quite the adaptable generalist and does well in wide array of wetland habitats. They are ‘perchers’ or stationary, territorial hunters. They perch most often upright on the tip of a stick, stalk of vegetation, flower, or some other pointed structure and remain motionless except for the craning of their necks to and fro to follow potential prey. When they spot a suitable snack, or an unwelcome competitor, they launch from their perch to pursue, before returning to resume the watch. Blue Dashers also readily assume the ‘obelisk posture’ where they raise their abdomen straight up into the air. Males do this as a means of saying, “This spot’s mine bud, you wanna fight about it?” to other intruding males. Both sexes will also obelisk when its hot as blue blazes out, pointing their abdomen directly at the sun to reduce their surface area and keep from overheating.
Blue Dashers measure about an inch-and-a-quarter in length with a compact frame and broad wings. Blue Dasher males and females are sexually dimorphic, and have markedly different color patterns. Males are powder-blue on their abdomen which is capped with a black tip, have aquamarine eyes and a white face, a thorax either solid blue or alternating with vertical streaks of pastel-yellow on dark brown, and have clear wings with black stigma and a varying degree of distinct smoky-brown staining across the base and tip of each wing. Females have two-tone red and green eyes like a half-ripe apple, a white face, clear wings, translucent-beige stigma, and a black and yellow body of alternating stripes, including distinct black pinstripes down the length of her abdomen leading to a black tip. Both sexes emerge from their larva with feminine colors and patterns, but males turn blue as they mature. Changing color after final molting is fairly common in insects, as their new exoskeleton has yet to harden and be flushed fully with pigments. This state is called being “teneral” and can result in some oddly colored insects for a couple hours. However, many dragonflies, such as the Blue Dasher, do a much more complex, gradual color change in their males, which can take many days to set in.
Like all dragonflies, the Blue Dasher has an aquatic larvae called a naiad, which prowls around underwater catching and consuming unsuspecting little aquatic critters. Many dragonflies’ larvae are picky about water quality and need to be in a relatively narrow window of water quality parameters to successfully make it to adulthood. But Blue Dashers? They just plumb don’t care! Apart from saltwater and extreme pollution, they can make do with most any wetland. This is why you can find Blue Dashers perched, patrolling, or pouncing on prey proximate to the perimeter of practically any pond, pool, or permanent puddle and darting and dashing down dikes, dams, and ditches. This adaptability has allowed Blue Dashers to become our most common and abundant species of dragonfly in urban and suburban locales, where human activities have radically altered, reconfigured, and impaired natural wetlands to meet the needs of civilization. Here, Blue Dashers provide an invaluable ecosystem service by scarfing down mosquitoes and other insects, both in the air and below the water, to control their populations. Blue Dashers themselves become food for Purple Martins, Barn Swallows, Flycatchers, and many other nimble insectivorous birds, and the odd Bullfrog or Bass. They’re thus not only a critical form of pest biocontrol and a major node in urban food webs, but an important pathway for nutrient cycling from aquatic to terrestrial ecosystems in your own backyard.
This week for Flora and Fauna Friday we’ll behold a beautifully blooming briar of a bean, Littleleaf Sensitive-Briar (Mimosa microphylla).
Littleleaf Sensitive-Briar is one of three species of Mimosa native to the Southeast but the only species native to South Carolina. It’s a low growing, sprawling legume found on dry sandy soils throughout the state, being most abundant on open hill tops in the Upstate and Longleaf Pine savannas here in the Lowcountry. It often forms dense, flat, circular mats of foliage radiating out three to four feet from its roots. Its thin, wiry stems and leaf veins are lined with enumerable fine hooked prickles, much like a Blackberry. And let me tell you, it’s a joy to walk through barefoot! These prickles defend the plant from grazing herbivores. The leaves of Littleleaf Sensitive-Briar are predictably little. Each leaf, as a whole, is about palm-sized but is bipinnately lobed, bearing roughly five-hundred individual leaflets, each not much bigger than a grain of rice. Beginning in May and continuing through June, Littleleaf Sensitive-Briar produces a profusion of eye-catching blooms along its trailing stems. We’re talking one-inch hot-pink spherical pom-poms orbited by golden pinpricks of pollen-packed anthers. These flowers not only pull in unsuspecting naturalists but have an almost magnetic draw on native bees, who clamor all over these fluffy flowers, sweeping up as much pollen as they can muster. These flowers mature into a string bean looking seedpod thoroughly cloaked in a shield of fine prickles.
Now, let’s take a moment to think on this plant’s names and what they mean, starting with the genus Mimosa. Apart from being a legume and sharing a similar leaf and flower shape, Mimosa species are only distantly related to the invasive Mimosa-Tree (Albizia julibrissin), which bears a similar common name. Mimosa is a name often applied commonly to members of the Mimosoid clade of legumes, which all have similar spherical flowers. (And, if you’re wondering, the mimosa cocktail is named after a different Mimosoid plant from Australia, which has bright yellow pom-pom flowers.) However, this unique but shared name belies another similarity. The term “Mimosa” boils down to meaning “to mime” or “mimic”. The leaves of Littleleaf Sensitive-Briar, as well as numerous other Mimosoids and other legumes with a similar finely divided leaves, can move! They are able to fold up their leaves when touched, ‘mimicking’ animal movement, at least as far as early botanists were concerned. They do this through the manipulation of osmotic pressure in specialized cells at the base of each leaflet. Running your finger down the midrib of a Littleleaf Sensitive-Briar leaf is all it takes for them to clam up.
Littleleaf Sensitive-Briar and its relatives fold their leaves for two reasons, to make it more difficult for things to eat their tiny leaves and to save water. When folded, the leaflets point upward. This improves its odds against all kinds of herbivores, even if just slightly. For big grazers like deer, this makes the plant look small and wilted, and assumedly less appetizing. For small browsers like mice, it points the leaflets away from their reaching paws and nibbling mouths, making it harder for them to avoid the numerous prickles along the bottom of each leaf stem. And for insects crawling on the leaf itself, pointing the leaflets upward forces them up into the blistering sun and the line of sight of any patrolling wasps and birds. Their leaves also fold up in the rain and strong wind, which helps protect the fragile leaflets from being battered against their surroundings. Apart from folding when touched, Littleleaf Sensitive-Briar also folds its leaves up based on environmental cues at night or during extreme heat, to help conserve water. A folded leaf has less surface area and thus transpires less water at night while idle. Similarly, a folded leaf points towards the sun and thus captures less sunlight when it is too hot or too droughty for the plant to keep up with the water demands of peak transpiration. In fact, the finely divided leaves and low growth form of Littleleaf Sensitive-Briar are both adaptations for heat, just different sorts. Finely divided leaves maximize the ratio of their perimeter to their surface area. This promotes air circulation around and through the leaf, helping it to avoid overheating under intense sunlight while it cranks out as much sugar as it can. The sprawling growth form of this plant is an adaptation to a different heat, fire specifically. Littleleaf Sensitive-Briar needs regular fire to keep the land open enough for it to persist. By staying short and low, it gets readily burnt up by fire. Yet, since it loses little resources in the fire, it can rapidly regenerate from its roots back to what it once was and continue on as normal.
