Every summer, almost every day, I go out in nature with my mind set on murder. Sericea lespedeza is my quarry, an innocuous-looking plant that spreads like a virus. It can out-compete even native grass. I’ve spent hundreds of hours spraying this loathsome nemesis and killed thousands of individuals. And yet, I still find survivors taunting me, sometimes within inches of my tire marks from earlier raids. How could I have missed them? The plants recently set their flowers, guaranteeing that they will be back next year.

On my outings, I’ve occasionally come across a strange plant known as Cuscuta pantagona Engelm, alias field dodder. The weed book describes it as a “dense mat of yellowish, leafless, threadlike, branching vine.” To me, it resembles a decomposing net, like the kind fishermen use to catch bait fish — or one of those 2,500 pages bills Congress likes to churn out to stifle economic growth. It’s one of many botanical curiosities that make life in the country interesting. And since I rarely see it, I’ve given field dodder scarcely a thought — until this summer, when I came across a sprawling infestation of it.

The spectacle was horrifying: A vast web of stringy fibers was crawling over acres of precious prairie. For a moment, I forgot about sericea lespedeza. Field dodder had my attention. It was on the move. Apparently, something had happened in the environment, some secret door had opened and this abnormal alien had seized the opportunity to run amok. “Doddering” conveys harmlessness and frailty. But a little research informed me that field dodder is “a plant from a horror movie,” a parasite that uses “fangs” to suck the life out of other plants. Also known ominously as “witches shoelaces” and “strangle vine,” field dodder has no leaves, essentially no roots. This creature from nature’s grab bag of grotesques hardly seems to be alive.

The sinister thing about field dodder is that it doesn’t find its victims by chance. It “sniffs” them out, follows their scent and then strikes. (Researchers are working to find which part of dodder acts as its nose.) This faceless, homely-looking derelict seems to harbor a kind of malevolence. Moreover, if it can smell, perhaps it can also, in some inscrutable way, “see.” I shuddered at the thought that, as I passed by on my four-wheeler, it had been watching me.

You may ask why a professed nature lover would declare war on natural things. The answer is that if I “let nature take its course,” my prairie restoration project — which has been a boon to wildlife — would be doomed. In a few years I would have a monolithic crop of lespedeza. Thorny hedge trees would choke out all other life. And now field dodder threatened. I added it to my “most wanted” enemies list.

I could win the war on sericea lespedeza if I abandoned spot spraying and blanketed the meadows with chemical. But that would mean losing purple prairie clover, partridge pea, catclaw sensitivebriar, Illinois bundleflower, Maximilian sunflower, butterfly milkweed, blacksamson, gayfeather and dozens of other beautiful plants beloved by bugs and birds.

Field dodder is another matter. According to what I’ve read, it can be exterminated only by killing the plants it feeds on, which sounds like destroying the village in order to save it. I console myself with the thought that in the last dozen years, plagues of ragweed, heath aster, yellow nut sedge, musk thistle and tall thistle have come and gone. I must wait until next year to see what field dodder has in store for me.

Meantime, the September prairie is lovely to behold. The hillsides are covered with golden sunflowers and glowing Indian grass. Butterflies and bees and migrant birds are in the fields. But my sleep is troubled with visions of field dodder, creeping toward the house, trying the windows and the doors, violating the peace of the country with its hideous laughter, sniffing me out, baring its fangs.