Old horror movie poster with a plant attacking people

While it may not be the most widespread or destructive of the many exotic, invasive, plants that have infested the remaining wild landscapes of Southern California, Sticky Snakeroot (Ageratina adenophora or Eupatorium adenophorum) is, in my opinion, one of the absolute worst.

Also referred to as Eupatory or Croftonweed, Sticky Snakeroot was originally imported to California from Mexico as an ornamental potted plant. Like many other frivolously imported species, it soon “escaped” the nurseries and flower shops, moving quickly into the wild with disastrous results. You’ll now find it on the California Invasive Plant Council’s list of destructive, non-native species, but Sticky Snakeroot is, in fact, a global scourge, considered a “noxious” invasive in Hawaii, as well as in Australia, New Zealand and parts of Asia.

A moisture-loving plant, you can see it here in Southern California subjecting streambeds to literal strangulation in most of our local canyons, crowding out the native flora. This has a negative impact on native wildlife as well, disrupting, as it does, the food web upon which it depends. Heavy rain and subsequent runoff will occasionally dislodge the shallow-rooted Sticky Snakeroot from canyon bottoms, providing a breather for this embattled microenvironment, but not for long. Just one surviving plant will generate tens of thousands of pernicious, wind and water-bourn seeds.

While Sticky Snakeroot is one of many exotic species targeted for control in the U.S. Forest Service’s exhaustive “Angeles National Forest and San Gabriel Mountains National Monument Plan for Invasive Plants,” if anything at all is currently being done to combat this extremely aggressive plant as it spreads into nearly every riparian habitat in the forest, it’s hard to see that it’s having much of an impact. And while I am generally disinclined to vigilantism, I will admit here that I have attempted to fill the vacuum on occasion, futile as it may seem, by ripping it out with my own bare hands.

“But, why would anyone pick on a poor, innocent little plant like that,” you might be thinking. Aren’t all plants inherently “good”? Well, yes and no.

In 2013, Lisa Novick (the former Director of Outreach and K-12 Education at the Theodore Payne Foundation, a California native plant advocacy group) posted an article on the Huffington Post entitled, “Just Because It’ll Grow in Your Yard Doesn’t Mean You Should Plant It.” I thought it raised an important and rarely debated point about the unintended consequences of the industrialized shipment of virtually the same nursery plants all over the world, even those that are non-invasive. This rampant “globalization” of gardening is erasing, Ms. Novick argued, the memory that there was ever such a thing as a set of geographically distinct, discrete natural environments. Instead, a diverse planet is being overrun by a bland, horticultural homogeneity that has no vital connection to the local fauna. (And, as we’ve seen with Sticky Snakeroot, tossing exotic plants willy-nilly into ecosystems to which they don’t belong can have devastating consequences.)

Novick writes:

“Worldwide, we are committing ecocide through our globalized gardens, due in no small part to the highly successful distribution systems of large companies selling mostly non-native plants. And to remedy this ecocide, here’s what we should do: Apart from the edibles we plant in our gardens to feed ourselves, we should plant primarily what is native to our region.”

Sounds sensible enough, but from reading the comment thread accompanying the article (no longer available online), you’d have thought Ms. Novick had proposed something unspeakable. These readers were outraged – outraged! – at the élite condescension of it all, responding with what were all mostly variations on “You can take my Hydrangeas when you pry them from my cold, dead hands.”

In other words, there are people for whom the very idea that a plant – any plant – could be a destructive force is an entirely alien and unwelcome concept.

While I am generally disinclined to vigilantism, I will admit that I have attempted to fill the vacuum by ripping it out with my own bare hands.

I’ve actually encountered this bias myself. On one occasion, I was at a gathering hosted by one of my neighbors, describing the horrors of Sticky Snakeroot in excruciating detail to hapless, fellow guest I’d managed to corner. Standing on a deck overlooking a dense, suffocating patch of the very plant in question, I had just finished explaining the cataclysmic effect that Sticky Snakeroot was having on the creek bed below when this guy awoke from his understandable stupor long enough to rise to the plant’s defense. “Hey, it’s just tryin’ to live,” he said. Undeterred, I replied, “Oh, really? Well, in that case, if you ever find yourself battling a life-threatening bacterial infection, I’m sure you’ll refuse antibiotics. After all, antibiotics would kill the bacteria and, hey, they’re just tryin’ to live.”

Actually I didn’t say that. I thought of saying it a week later.

But really, he was right. There are no “bad” plants. Sticky Snakeroot is just “tryin’ to live” in whatever environment it happens to find itself. It didn’t ship itself hundreds of miles from its natural habitat, a place where it fit in because it had co-evolved with other species in the same environment over eons. A human being has to decide that it’s a good idea to move a plant halfway around the world, thereby introducing it into vulnerable ecosystems where there are no natural controls to limit its spread.

So, while I agree that we shouldn’t project a human capacity for malign intent onto a plant, let us not shed a tear for Sticky Snakeroot. (The newts and frogs don’t have that luxury.) For that matter, let us hope for a greater organized effort to control Sticky Snakeroot and all the other escaped exotics – Cape Ivy, Spanish Broom and Tamarisk among them – and for a limit to their disruption of what’s left of our tattered local ecosystems. Let’s save our sympathy for the species that truly belong here, the Scarlet and Yellow Monkeyflowers and all the other beautiful and essential riparian plants currently under assault that are “just tryin’ to live.”

– Eric Ameria

© 2020 by LA Native Plant Source

A field of Sticky Snakeroot

Sticky Snakeroot Gone Wild. (Photo by Adrienne Simmons)

Sticky Snakeroot Must Die

At the risk of being thought an agent provocateur, I offer the following handy guide to ripping the shit out of some Sticky Snakeroot on your next hike. While it may be purely symbolic, this kind of guerilla “mechanical control” is at least emotionally satisfying. It’s best done before the plant has set seed.

Before you act, however, make sure you’re culling the right plant. A comprehensive description can be found in the Jepson Herbarium. You can also arrive at a definitive ID to confirm your visual observations with iNaturalist or other, similar apps.

Like other species that do best in constantly moist soil, Sticky Snakeroot has a shallow root system, making it relatively easy to pull it right out of the ground.

  1. Grab a handful of Sticky Snakeroot and give it a few tugs. It will likely pop right out, depending on the size of the clump. If it won’t uproot after a few tries, best to leave it alone. There’s more where that came from.
  2. Find a big rock or ledge upon which to deposit your uprooted plant, leaving it there to expire. Make sure that the roots are not in contact with the ground.
Pulled weeds pinned under a rock

RIP, Sticky Snakeroot!