Sundews

Still stuck in the throes of yet another long, hot summer accompanied by its burden of bugs, we seek relief from the bloodsuckers. Insecticide sprays, dusts, and foggers offer hope for stifling humming mosquitoes and gnats; buzzing bees, wasps, hornets, and flies; and stealthy silent ticks, spiders, chiggers, and fleas, but insecticides often come with health and environmental warnings. Bug zappers are obnoxious and ineffective in controlling mosquitoes and gnats, which forsake the lure of light for the more provocative scent of carbon dioxide released in human breath and sweat; furthermore, zappers spray insect germs, viruses, and body parts (ew!) and electrocute beneficial bugs. It seems we are doomed to practicing our fly swatter swings as defense. There is, however, an appealing option: cultivating carnivorous sundew plants. 

Charles Darwin... wrote “I care more about Drosera than the origin of all the species in the world,” which is quite a testimonial.

Sundews, of the genus Drosera, meaning “dewy,” are usually so inconspicuous we overlook their dime- to quarter-sized blooms, which grow close to the acidic, nutrient-deprived, silty soil of the bogs, swamps, marshes, and river banks where they thrive. After originating either on South Africa’s cape or in Australia, still the epicenter of sundew diversity, almost two hundred species of insect executioners migrated to every continent except Antarctica. Several North American species grow as native plants across the United States, minus some Southwestern areas. Humid southeastern states are a good fit for six or so wild-growing species, so watch your step and look for the miniature melodrama playing out in a swamp near you. 

Since they grow in soil lacking nutrients, sundews eat live insects for protein and nitrates. Without providing hands to catch, teeth to bite, or stomach to digest, Nature created a hungry beast in floral clothing. Sundew structure is ingeniously designed to efficiently lure, entrap, slaughter, and consume prey. The leaves hold the secrets of a Machiavellian ruse. Glandular tentacles that look like hairs on stalks protrude from the leaf’s surface and produce sticky, shiny droplets of sweetly scented mucilage that sparkle enticingly on the tips like perfumed dew drops. Makoto Honda, author of Carnivorous Plants in the Wilderness, lyrically describes them as “[g]listening in the sun like a cluster of diamonds, with their dew-covered leaves emanating the full spectrum of a rainbow,” a depiction that takes the breath away just as the tentacles swipe the breath from beguiled insects. 

[In the mood for another creepy plant? Indian Pipe]

When enticed prey lands on a leaf, its many tiny feet stick to the adhesive surface. Now things get really creepy:  The tentacles respond to the touch of the insect and the vibration of its frantic struggle, coming alive like the haunted trees in The Wizard of Oz to broadcast neural impulses and give other tentacles a heads-up. The tentacles bend inward to the center of the leaf and over the desperate victim, working in sync to move it to the middle of the leaf, where the glandular sessile hairs release an insecticidal mix of acidic enzymes, acting as digestive juices, that wash over the still live insect, if it has not died of fright. In some species, when prey is large enough to fight back, the entire leaf closes in a fatal embrace to secure it until the deed is done. Online slow-motion videos not recommended for the squeamish allow us to watch the entire macabre process. Suffocated and liquidated, the prey provides a protein-enriched stew of bug organs, slurped up and absorbed by the leaf in a bizarre external digestion process. With mission accomplished, the leaf uncurls, perhaps with a tiny belch, dropping its victim’s drained and dried exoskeleton. 

Although most of us are oblivious to the insectivores, the Gulf Coast region is home to five species of sundews growing in the wild and thriving beside major highways in heat up to one hundred degrees. In addition to causing frizzy hair, our oppressive humidity provides the incessant moisture sundews crave along with direct sunlight. If willing to do the research and the cultivation, anyone who finds the idea intriguing can start a small sundew plantation of ecofriendly exterminators. Seeds, plants, pictures of the many species, and growth requirements are available online, which is way easier than slogging through bogs in search of white, pink, red, purple, or orange sundew flowers accessorized with colorful spiky hairs. Experts advise against planting sundews in the ground, due to their specific soil needs, and suggest using small plastic or glazed pots filled with sphagnum or peat moss mixed with perlite or sand, placed in a saucer or tray containing pebbles and mineral-free water. Potting soil, fertilizer, mineral-ridden tap water, and compost are lethal to the weirdo plants, as is letting the water evaporate; a dry sundew is a dead one. 

Suffocated and liquidated, the prey provides a protein-enriched stew of bug organs, slurped up and absorbed by the leaf in a bizarre external digestion process. With mission accomplished, the leaf uncurls, perhaps with a tiny belch, dropping its victim’s drained and dried exoskeleton. 

Growing sundews in cooler climates usually requires terrariums. We, however, live in an oversized natural terrarium and can leave our sundew plants outside all winter if we choose a species compatible with our climate and stay alert for maverick cold snaps below thirty-eight degrees, which require covering the plants, although some varieties will return after a hard freeze. Come spring and summer, plants that have died back are rejuvenated and happily spread their tentacles to welcome the mugginess that mugs us and the bugs that bug us. Lucky us! With throngs of insect and arachnid varieties, our sundews can feed themselves, but many growers supplement the plants’ diet with beta fish food or squished-up bloodworms just to watch the plants’ reaction to touch and the dramatic spectacle that follows, just as Charles Darwin did in his years of illustrating and experimenting with sundews. The naturalist wrote, “I care more about Drosera than the origin of all the species in the world,” which is quite a testimonial.

I can envision these cousins of Venus flytraps perched on my porch. My mind’s eye sees a lovely Drosera rotundifolia glistening and winking seductively at gnats and mosquitoes, but wait! What about hard working honey bees, beautiful butterflies, and ethereal damselflies? Are sundews no better than bug zappers? Well, yes, because they are one of the tiny cogs of our sprawling ecosystem. Insects are notorious for eating plants, so sundews may be Nature’s version of checks and balances. Maybe we could train our plants to have discriminating palates that would encourage feasting on destructive insects while sparing the beneficial, but I suspect the sundews will hold tightly to their traditional protein diet of any insect that flies or crawls or hops, relentlessly whispering “Feed me” to the thrumming humid air.  

“Sundews – get you some,” Lucile suggests while swatting flies and slapping gnats at home in Vicksburg, vowing to have several varieties of sundews established before the arrival of next summer’s invading swarms.