It’s a scene straight out of a horror movie: a thread-like orange stem emerges from the ground, circling around counter-clockwise, searching by smell* for a potential victim. When it finds an unsuspecting, vulnerable plant, it wraps around it and pierces the victim’s stem, sucking water and nutrients from the host plant like a vampire. This nightmare is called field swamp dodder (Cuscuta campestris gronovii)**. It’s the creepiest native plant I know!
See how those orange stems are reaching out, searching for its next victim?
Doesn’t it look like witches hair? Photo credit: Scot Nelson
So you can imagine my dismay when I found this by the used-to-be-pond, wrapped around my one and only cardinal flower.
The only way to eradicate dodder is to pull up the host plant. I didn’t want to pull up my precious cardinal flower, so I cut it off at the base and hoped that was good enough. I also searched the area for other plants in dodder’s stranglehold and pulled them up. For a plant that’s supposed to be such a nightmare, I didn’t find that much. That wasn’t too reassuring, as I wasn’t sure if I just hadn’t looked hard enough or had indeed caught it early. I’ll have to revisit the area next year to see if I find more.
Of course, it’s best to pull the host plants before the dodder has gone to seed. Here you can see both flowers and developing seed capsules. (Click to enlarge)
Yes, it’s creepy.
*It detects volatile chemicals released by the (potential) host plant and grows toward them. (Don’t believe me? Read this.) We use our nose to detect volatile chemicals in the air and we call it smelling. So I’m saying dodder finds its victims by smell, even though it doesn’t have a nose.
**After I wrote this post, I realized I had misidentified the species. To be fair, dodder species “are distinguished by tiny differences in their flower structure,” as the Connecticut Botanical Society points out, so it was an easy mistake to make. And Minnesota Wildflowers notes “C. gronovii appears (at least in literature) not to be the pest that some other species are capable of.” So perhaps I don’t need to be quite so scared of this plant.
I have a dodder in my garden. They tell me to remove it … and I peel it back from the sky down to the roots. Slowly I am winning.
I’m glad you are winning. I read that you are supposed to pull all the plants it infiltrates as well as the dodder itself, but I couldn’t bear to pull my cardinal flower. I just cut it off at ground level and hope it comes back from the roots next year–dodder-free.
Dodder is a parasitic plant that INITIALLY has roots as it wraps itself around its host plant, but as it sends out suckers that penetrate the host, its roots die.
Fun fact, dodder gets its species name (gronovii) from the Dutch botanist Jan Frederk Gronovius, the teacher of Linnaeus (inventor of modern systematics).
Susan Farrar
WisconsinPollinators.com
I did know it initially has roots, Susan. Many of the sources I consulted said if the plant didn’t find a host within 24 hours, it died. Perhaps it was a bit of poetic license to leave out mention of the roots, but it seems for most of dodder’s life, it doesn’t have roots.
Kathy, You might be interested in reading (if you haven’t already) Daniel Chamovitz’ book What a Plant Knows. He touches on, if you’ll forgive the unintentional pun, all kinds of sensory abilities plants have – including “smell.” It’s a short, interesting read and very sciency.
Helen, I have read What a Plant Knows, and it’s what inspired me to use the verb smell to describe how dodder detects its victims.
Fascinating discovery, Kathy. Plants never cease to amaze me! Thanks for the great photos and info. Yes, the perfect post for Halloween! 🙂
It is really, really creepy. I hates it precious. Happy almost Halloween.~~Dee
Creepy dodder is perfect for Halloween. I’d never heard of this plant. Yikes! Hope you’re free of it now.
Great scare Kathy! Fun post. Happy Halloween to you.
Ok, that is a creepy plant! I have seen it before, but didn’t know what it was. I love how plants sense the world- it’s different than mammals, but so effective and fascinating.
I have never heard of such a plant. I will be on the lookout for it. It is a creepy plant. I have no doubt that plants can smell or how ever you want to describe it. They are so fascinating, even in their creepiness.
How awful and “unearthly”-
That is creepy! Yes, I remember seeing it here occasionally, but believe it or not it’s a species of special concern and critically imperiled here in Wisconsin (where it is also native). Great information and post title!
Beth, I didn’t think to check its status in NY. Turns out there is a endangered dodder in NY, smartweed dodder. https://www.acris.nynhp.org/guide.php?id=8996 It’s possible that this dodder is the one growing on my land. It certainly reminded me of smartweed. The article lists some other NY dodders: Cuscuta cephalanthi and C. coryli. Hmm. Further research is needed! Maybe I shouldn’t be ripping it out.
That is indeed the creepiest native plant! So glad you shred this scary plant with us. xo