Ladies and gentlemen, we have a new and ugly invasive species to loathe and condemn! Let's put our hands together and give a big Minnesota welcome to the Japanese knotweed!
But first, let us recall some other invasive plants and critters we've come to despise.
You all know the Asian carp, which can leap 10 feet out of the water, slice you with its fins or just give you a concussion. Assault Fish, in other words. They're not populous enough to the point where someone has to stand in the prow of a motorboat with a baseball bat. Yet.
Then there's the spiny water flea, which eats the zooplankton that native fish enjoy. If they knew how to share, this wouldn't be bad, but picture a binge eater who goes to Old Country Buffet with a Shop-Vac.
Don't forget the hydrilla plant, which forms underwater mats of ooky gunk (proper scientific taxonomy: ookus gunkus), which causes total disgust when you step on it. The stuff was introduced in Florida when people used it in aquariums, and somehow it made it into the waterways — possibly because Floridians got tired of maintaining their aquariums and drove into the countryside to dump the contents, telling the kids "the fish will find a nice farm to live on."
And of course there's Eurasian milfoil, which has always been at war with the Eastasia milfoil. It reminds you that every invasive species is slimy, ugly, useless or disfiguring. No one would complain if Eurasian milfoil made the water cleaner, flourished for a week and emitted bubbles that perfumed the air when they rose to the surface.
At least they could have the decency to strangle those disgusting zebra mussels, which cut your feet and spread avian botulism as their way of saying "thanks for having me over, guys." Birds are one of the few natural predators they have in North America, but until I see lots of gulls wearing snorkels, I'm not putting my money on that.
And we're all resigned to the Emerald ash borer destroying every ash in the state. It makes the Dutch elm beetle seem like part of the family, like an old relative who falls asleep and burns a sofa cushion when he drops his cigarette.
But back to the newcomer, Japanese knotweed. It looks like bamboo. It grows up to 7 feet tall, puts down roots to a depth of 10 feet and is capable of growing through concrete. Wonderful.
One man is responsible for its introduction: esteemed park planner Frederick Law Olmsted, the most brilliant landscape architect of all time. Did a little thing in New York called "Central Park" that you might have heard about. He thought the Japanese Crapsticks would be great for the highways in a new Boston park system but probably didn't envision them marching north to Maine, south to Louisiana and west to Duluth. Of course, he was active in the late 1800s, and if you'd told him the plants would be a pest in 2013, he would have invited us all to visit his grave and yell at his tombstone.
Since its importation, it has garnered many names, and I'm not making this up: monkeyweed, Donkey Rhubarb, Hancock's Curse. (The last one refers to the Englishman who introduced it to his garden and let it run riot, destroying everyone's property values.) No one calls it Olmsted's Follyweed, but perhaps they should.
If you Google the stuff, you'll find something interesting: People insist you can eat it. Picked at the right time, boiled, smushed and blended with lemon and sugar, it makes for a tasty pie filling. Of course, so does newspaper, if you add enough sugar.
It has another function: Traditional Asian medicine uses the roots as a laxative, although I think just the sight of the stuff will probably have the desired effect. Other studies show that the chemical present in Hancock's Curse can prevent joint disease, although studies show it can also aggravate arthritis. You have to catch it on a good day, I guess.
So what are we to do? We can eat it, but you go first. (I know that whenever I'm served rhubarb pie in the future, I will ask if it's Donkey Rhubarb.) Or we can just say it's bamboo and send out teams of DNR workers to paint the bears white with black accents, and presto: pandas. Everyone likes pandas. Tourists will come.
Next to watch out for:
Mediterranean Sloth Weed
Hibernian Slice-fish
African Moan-grass
Makes you wonder if someone in Australia is dealing with an infestation of Minnesota Niceweed, which is the most unusual invasive species of all. An aggressive invader is one thing; you can spray chemicals. A passive-aggressive invader is another thing entirely.
It doesn't take over your yard. It just stands off to the side and notes that it wouldn't have planted those geraniums — but it doesn't want to be critical.
jlileks@startribune.com • 612-673-7858
