Creature Feature at Cranberry Glades

I'm just not ready to leave the bog. One might say I'm "bogged down."

The pitcher plant (species Sarracenia pupurea venosa)and the sundew are two of many plants I saw on my visit to Cranberry Glades (see previous post The Boreal Bog). These plants lure insects, trap them, then slowly digest them. I had to learn more-here is what most impressed me. If you are so inclined, while you read, ponder the Adaptation process that resulted in such elegant solutions.

Carnivorous plant species number more than 500 and grow all over the world. They often live in waterlogged areas such as swamps and bogs. These places are deficient in nitrogen and other trace minerals important to plant physiology. So it is thought that carnivorous plants have developed strategies to get some of those needed substances from the bodies of animals-such as insects, spiders, and even bigger prey. Their strategies often require glands that either fill with water or must remain moist. The details of their dining habits bring to mind the narrow escapes of heroes like Luke Skywalker and James Bond. If they could talk we might hear something like: "Welcome, Mr. Bug, hahahahahahaha!"

The Pitcher Plant

The leaves of the pitcher plant form cups, indeed another name for them is "hunter's cup. " Supposedly the rainwater contained in the cup is safer for a human to drink than the acidic bog water in which it grows. On the rounded lip of the cup are red veins that attract the attention of insects--possibly due to the resemblance to carrion.

Alighting on the slippery edges of the cup, an unfortunate critter then finds it easy to lose its footing and slide into the gaping maw. Perhaps it even experiences Vertigo. A spiky fur points downward to deter any attempts to escape. Imagine trying to climb the slippery walls while treading water in a deep cistern and you've got an idea of the insect's experience. But that's only the start of the macabre process.


In a sarracenia purpurea, the insect drowns and over time the water dissolves the insect's soft tissues. Special cells at the base of the cup absorb the nutrients. Some other species of pitcher plant actually contain a fluid similar to that found in mammals' gastric systems. That would certainly help digest something like a large rat. The biggest known pitcher plant does just that. The cup of the Nepenthes Rajah of Asia can grow up to 20 inches long, 6 inches wide, with an opening of 3 inches.

Biologists who do things like dissect pitcher plants are amazed at the quantity of indigestible exoskeletons that collect in a "boneyard" at the bottom of the cup. I wonder if the live insect can see the gruesome remains of previous victims at the moment of his or her descent into insect "hell." To an entomologist however, I'm sure those are Lovely Bones.

The Sundew

Sundews belong to the largest genus of carnivorous plants Drosera, with more than 200 species. The way the sundew hides menace behind whimsy, you might suspect it came from outer space. At Cranberry Glades, sundews dot the surface of the moss like countless simpering, "happy faces."

But each tiny leaf is far from being a Little Miss Sunshine and more like the product of a Bad Seed-- at least from an insect's point of view. There is a glistening drop of "superglue" at the tip of each of the fine hairs on this little damsel. Insects alight expecting a sweet reward of nectar. But touching even one hair can ensnare. The greater the bug's Frenzy to escape, the more it entangles itself in other hairs.

The rest of the hairs on the leaf then bend lovingly over the prize until it is clenched firmly as if in a many fingered hand. The process is not as fast as the abrupt snap of a Venus Fly Trap, but still amazingly swift--for a plant. It takes about one hour for the insect to be fully embraced in a deadly kiss. Pressed firmly against the enzymes on the surface of the leaf, the insect innards are liquified. Digestion may take several days. Afterward the hairs return to their original positions. For a time the hairs stay dry and the remains of the day are soon gone with the wind.

The biggest species of Sundew is South Africa's Drosera Regina with leaves up to more than 22 inches long. In Australia a sundew of similar size makes a banquet of frogs and lizards. Crocodile Dundee types boast of finding sundews growing in clumps that feast on the occasional rabbit or squirrel.

Darwin was the master and commander of evolutionary thought, but nevertheless was humbled by the sundew. He wrote to a scientist friend that "I care more about Drosera than the origin of all the species in the world." Its not surprising that the ingenuity of carnivorous plants continues to seduce and ensnare our fascination. We are willing victims.

ABC Wednesday For some fantastic images of these Cranberry Glade plants go to Squirrel's View.

Alien Invaders

Alien species, non-native species, exotic species. These are plants, animals or other organisms that have been abruptly (compared to natural migrations) introduced to an ecosystem, usually by human doings-often accidentally, but sometimes intentionally. This phenomenon has caused dramatic changes worldwide, and continues to do so.

I recently learned that many of our most familiar "wild" flowers are non-native and have been around for centuries. Seeds hitched across the Big Pond with early European immigrants. Each summer I'm happy to see the 6 foot tall flowering spikes of fuzzy leaved Common Mullein that stand at attention like soldiers reviewing a parade. What country girl hasn't picked a bouquet of Queen Anne's Lace and marvelled at its umbrella of tiny white florets?

These roadside weeds are rather benign, but for an example of negative effects, one word: kudzu. A noxious vine, kudzu strangles and smothers everything in its path. It was aggressively planted by the U.S. government in the 1930's for erosion control before it was discovered that in our humid southern states it grows just too well.

European starlings (Sternus vulgaris) were brought to North America by a man who wanted to seed our continent with all the birds that are mentioned in Shakepeare! The descendants of the original 75-100 birds released in New York's Central Park in the 1890's now number more than 200 million. Starlings have voracious appetites, migrate in flocks of up to 100,000 birds, and have contributed to the decline of the bluebird, purple martin and tree swallow.

Not all non-native species are home wreckers, but those that are earn another moniker: invasive, although this term is passing out of favor in ecological circles. (Truth be told, a native species may be invasive as well, meaning it rapidly colonizes an area, such as the Maryland state flower, the Black-eyed Susan. )

By any name, an exotic invasive species does not "smell" sweet-- but through no fault of its own really. In its homeland, it probably evolved to be in relative harmony with its surroundings. But transplanted to a new environment, it may have few or no natural predators, no competing species, and other species may have no natural resistance to it. The result is imbalance and perhaps irrevocable degradation of indigenous flora or fauna.

Since species are interdependent, when one species goes it can take others with it in a chain reaction. This dynamic has severely impacted the vulnerable islands of Hawaii. Seventy three percent of U.S. extinctions have occurred in Hawaii. Feral goats, pigs and sheep are some of the worst offenders there.

We learned how wolves benefitted the ecosystem when they were eradicated (by homo sapiens) from places like Yellowstone. Without wolves, elk proliferated and began overgrazing vegetation, which in turn affected other species, increased erosion, and impaired water quality. The ecosystem there is now mending due to the much publicized, and controversial, re-establishment of wild and free wolves.

Growing to 60 feet, the American Chestnut was formerly a dominant tree throughout our eastern forests, until a blight hit it early in the 20th century. The culprit? -- a variety of chestnut brought here from Asia that had resistance to the blight. Scientists are working to develop resistant strains of our native tree in hopes of restoring the chestnut to its former place as king of the forest. Doing so could have a substantial impact on mitigating climate change.

It is sobering when I consider not only changes I've witnessed in a half century of outdoor wanderings, but just recently. This past spring I saw infestations of garlic mustard in shady glens along the Potomac, choking out trillium, mayapples (see photo left), jacks in the pulpit, and other delicate native wildflowers that were flourishing only a few springs ago.

From my childhood, I remembered the path at Cunningham Falls State Park as a magical tunnel formed by the delicately needled branches of eastern hemlock trees. Wanting to get an early start on sharing my love of nature with my grandson, I took him there when he was only one year old. The magic remained. While perhaps not as plentiful, the hemlock branches still drooped gracefully above us like tiers of shyly lowered eyelashes. My grandson is now almost five years old. On a recent solitary visit, I felt like a survivor on a battlefield. The skeletons of eastern hemlock trees littered the forest floor or stood gray and silent like ghosts.

In this heavily used park, where biodiversity has already been severely diminished by grazing white-tailed deer, I suspect the hemlocks may have been even less resistant to the Wooly Adelgid-an introduced aphid-like pest. To add insult to injury, Japanese Stilt Grass was making rapid headway in crowding out native Lady ferns. (Where's Waldo the fern?) The overall effect was one of barren sterility.


Young families walked past me as I stood shell-shocked. They were blissfully unaware of what they had missed. But I knew, and mourned their loss. Especially on behalf of the children.

At my feet, a huge black beetle scurried at a surprising pace across the path to avoid being trampled. He frantically pulled some leaf litter over his head and body, obscuring not only himself but his own vision. Although tempted, I didn't disturb him. I knew how he felt.

ABC Wednesday

To Be Born

Have you ever seen a just-born child? The small figure is luminous--so infused with the energy of becoming that the outlines of his or her body appear to waver like a mirage. Even the most cynical of us can't help but be awed. The word miracle rises to the lips.

I had a similar experience on a dragonfly foray with a naturalist friend last Saturday.
We were at a low water bridge on the Cacapon River in Morgan County, West Virginia. It was one of those days in May that foretell the heat and humidity of July. We seemed to have entered a giant incubation chamber, for life was hatching all around us.

Cool water from weeks of spring rain flowed between banks of freshly leaved trees, newly sprouted grasses, and wildflowers budding or in bloom. The sun's rays danced through the air, setting all things green ashimmer.

Tiger and zebra swallow-tailed butterflies flitted in small clouds and flocked to sip at puddles. Their wings looked impossibly fragile. Not a tatter or speck of dust marred the patterns of creamy yellow, pale celadon and inky black. A drop of columbine red punctuated the base of each wing like the dot of a exclamation mark.

A green heron with a watchful eye rimmed in gold perched motionless on a snag midstream. Flashing scarlet helmets and bars of black and white, two male red-bellied woodpeckers alighted at the base of a sycamore. They hesitated, artfully askew on the pale trunk. I imagined them as bright enameled jewelry adorning the breast of a 1940's screen siren.

Dragonflies had recently passed through their metamorphosis from aquatic larvae to airborne adults. They cruised the river's edge like miniature hovercraft. Each was escorted, in perfect formation, by the image of a watery twin.

Low to the ground, tiny native bees meandered here and there to gather nectar. A brown water snake slithered through the shallows. All the while, the insistent murmur of American toads played as background music.

My friend snared an Applachian Jewelwing damselfly with her net. It was an immature male--still only half dressed in its armor of emerald green. She gently folded its wings to meet above the thorax and passed it to me. The finely veined gossamer was slightly damp and clung to my fingers.

The word nature descends from the Latin nasci "to be born." Capturing bits of data is often the goal of observation in the field. There is a special excitement as another piece of a giant puzzle slips into place. But what I most enjoy is seeing the world as if revealed for the first time. Deep in my bones, I sense the truth of how all of us--plants, insects, animals, humans--are made of the same stuff. We are born from the same mother. My heart flutters as I whisper a single word: miracle.