Ep. 159 Mistletoe Show: Learn about this holiday parasitic plant | #GoodGrowing

Welcome to the Good Growing podcast. I am Chris Enroth, horticulture educator with University of Illinois Extension, coming at you from Macomb, Illinois. We have got a great show today. Pucker up, baby, because we're talking mistletoes. And we're gonna get into stories, legends, and what the heck is this plant?

Is it a plant? I don't know. We're gonna answer a lot of these questions, and you know I'm not doing this by myself. I am joined as always every single week by horticulture educator Ken Johnson in Jacksonville. Hey, Ken.

Hello, Chris. Sure. We're talking before we started here. It's like being in school again, all the studying. I know.

To do.

This is this is becoming difficult, arduous, brain numbingly, lot of reading to become temporary experts in these plants that we've talked about these last few weeks. So thank you for helping me out, Ken.

Oh, thank you. I think it's been fun. I don't remember how I don't know how much this I'll remember come Exactly. Couple weeks from now.

Yep. What's mistletoe? So what's that? Or ten minutes from now. Mhmm.

I I I really only remember, like, movie quotes and things like that. And so I think it is comes from, this is the the second Batman movie with Michael Keaton. Not Batman forever. I'm not gonna think of the name. But Catwoman says the quote about mistletoe, and then Batman, I think, responds.

So she says, kiss under a mistletoe. Do you know mistletoe is deadly if you eat it? And then Batman says a kiss is even deadlier if you mean it. Oh, man. See, I don't remember that stupid stuff, but I'm not gonna remember things that apply to my job about plants.

Yeah.

That's all good. Come in handy when you're playing playing trivia.

Exactly. Yeah. And so yeah. We'll we'll see if we maybe can help out our listeners, viewers today with some mistletoe trivia. And let's just go ahead and kick this right off with the legends, the traditions, the mythology.

And I know this started everything I read, the first opening sentences, druids did this. And now if if you knew me as as a younger lad, you'll know that when it comes to D and D campaigns, video games, I always go for the druid. So I'm into this this druid stuff. But it began as a druid tradition. But I think didn't it move on into, like, Norse mythology, Ken?

What's more of this backstory of a traditional mistletoe?

So there's all kinds of I think it seems like almost every culture has got some kind of mistletoe mythology or legend, however you want to refer to it. So I think yeah. I think the two I think more commonly known commonly talked about are the the druids and the Norse mythology. So with Norse mythology, it's with the god Baldur. I don't know if I'm pronouncing that right or not.

But is a beloved god and was having and there's I don't know how many different versions I've read of this, so I don't know what the actual Norse belief was. But he was having nightmares about being killed or it was prophesied that he was going to be killed in some way. And his mother, Frigg, who I believe was Odin's wife. I'm not up on my Norse mythology. And who is also his mother.

She's the goddess of love. She went around and secured oaths from every animal and plant on earth that they would not kill him. Bal'dur. All except one mistletoe. They either overlooked it in some stories or in others is purposely didn't ask it because it's so small it wouldn't hurt them.

And then in some versions, you know, all the other gods start throwing stuff at them, you know, trying to kill them and they can't kill them because everything's given an oath not to kill them. But then Loki finds out that she didn't secure an oath from Mistletoe, fashions a spear or an arrow out of it, and either he throws it or gets another god to throw it at him and it kills him. Because he didn't have Mistletoe didn't promise not to kill him. So he dies. And then there's versions where he goes to Hel, H E L, the Norse underworld.

And they try to secure his freedom and everything has to weep for him. Loki in disguise refuses not refuses to, so he remains in hell. Other versions, Frigg starts crying and that creates the berries of mistletoe as she declares that, you know, mistletoe will be a symbol of love, not death. That's supposedly what we kiss under it. Now I think that's a more more modern romanticized version of it.

I think there's also versions where Freak finds out who does it and tortures them for all eternity. So kind of of pick your point

in Vikings. Love those Vikings. Right? So there's a lot lot to unpack there. Apparently, Loki had it out for Balduar.

He did not like that guy. So very, very interesting stories about how we now have mistletoe as a Christmas holiday tradition. And I it it probably I would guess mistletoe being an evergreen probably got lumped in a lot with some of those other evergreens that, you know, with that kind of also came from, like, Roman German traditions of bringing in greenery into the home to to decorate, to ward off evil spirits during the darkest, shortest days of the year. And and I I'm guessing mistletoe being one of them evergreens out there got lumped into the whole boughs of Holly and stuff like that. And it just so happens that it's got a a great story about Loki.

I didn't see that in the Disney series about Loki. So I'm gonna look for that. Yeah. I I didn't see that part. I missed it.

And I think another thing with mistletoe, again, it being evergreen, finding it on deciduous plants, it's I think a lot of times associated with fertility as well. So I think there's I found some stuff in Austria where mistletoe will be placed in either couples beds or in their their rooms to encourage conception. The anu. Indigenous people in Japan would soak their seeds in it. That would supposedly help their harvest the next year, their grain seeds and stuff and all kinds of of other things along those lines.

That's that's why my mother-in-law gave me mistletoe for my wedding anniversary. I thought she was trying to kill me. She's just trying to make me more fertile, so more grandchildren. Very interesting. Interesting.

So when you talked about Frigg's tears, mistletoe I guess let's back up. Mistletoe is found all over the world. Many different species. There's not just one. There's all different types that some of them are very specific on the plants that they grow on, and some species of mistletoe will grow on a multitude of different plants.

So there's there's a lot of different things here we'll try to unpack today. But but when it comes to the berries and Frigg's tears, there are mistletoes that have kind of a white some of the pictures I saw were almost like a clear white colored berry.

Translucent kind of.

Yeah. Translucent, which would would really that makes more sense than Frigg's tears become the berries. And so, yeah, I I I like that story and how it kind of comes together with that botanical reference.

And then that I mean, that's was it the European? I can't remember the scientific name now. One of the European ones I think is white and the American is also white. But for a lot of the mistletoe's are tropical or subtropical and there's all kinds of different color berries. It's I think in our holiday traditions we're talking about white, but you look around the world there's all kinds of different colors.

Yeah. Well and and the things that that you dug up, Ken, a lot of these articles and and as you mentioned, there's mistletoe, Japan. We it's in Australia, which I think it's really interesting that it is in Australia because for the the time period that Australia has been separated as a continent from a lot of the rest of the world, a lot of things evolve differently in Australia. And and when it comes to every animal down there, an insect, it just wants to murder you. But it it but Australia even has its own mistletoe.

And so I don't know how it's murderous intent as with some of the spiders that will actively chase you. Extra But Extra toxic. Yeah. It's it's super duper scary, super duper poisonous. Don't know

that for sure.

Yeah. We don't know that for sure. Don't go

to us on that.

Yeah. Better call someone in Australia. So I guess let's let's switch gears a little bit and talk about mistletoe in nature. And maybe more specifically, our part of the world, Illinois. Do we have mistletoe in Illinois, Ken?

Yeah. We've got at least one species. I've only found, you know, people writing about one species. So that's the oak, mistletoe, American mistletoe, got a couple other names too. But it's primarily going to be in Southern Illinois, like far Southern Illinois.

So in Jacksonville and Macomb and even further south from that. But it's it's not going to be found. But we do have one species. It's primarily obviously found south of that. But again but most species again are more tropical, so tropical.

There are some dwarf mistletoes out west. From my understanding, dwarf mistletoes only attack conifers. So out there, they're they're seen as a pest or disease in the lumber industry and forest settings because those will event can eventually kill trees. I think the stuff we have more on the East Coast, the American mistletoe, probably could kill trees. I don't think that's really a concern.

It it's probably really one of those things where it's like a healthy tree might be able to tolerate a little bit of mistletoe growing on it. But then, you know, I decide I wanna put a patio in in the shade of this tree, and there just happens to be mistletoe there. And I decide I wanna hang one of those funny little faces on the trunk, and so I nail it into the trunk. And so all of these multiple things, stresses on this tree, mistletoe's not helping it. And it's just one of the many factors, I would suppose.

Yeah. So the the species we would find in Illinois, they're in the Eastern United States as the Forodendron lucarpum. If I'm pronouncing that right.

I think so. I and I feel like we are obligated to say this because every single article mentioned this, what that translates into, foro dendrum, the genus name, which is a dendro, which is tree, and I'm guessing four o is thief. So it translates to thief of the tree. And so just because everybody mentions it, I guess we better mention it now too on this podcast. And now you've heard it.

You're welcome. Thank you. Yes.

Sure. Just tell them what mistletoe means?

I don't I have no idea. What is this? Mistletoe sounds like a military term

or maybe a medical condition. So it comes from old English. So or for Anglo Saxon word is mistletoe, which means dung and tan means twig. So mistletoe is dung on a twig.

I knew that. But I forgot. Thank you for reminding me.

More trivia information there for you.

Yes. Dung on a twig, thief of the tree. So I guess it sounds like humans don't like this particular plant. And as you mentioned, it kills trees out west. It's kind of an issue for the timber industry.

So humans have really viewed this as a pest or a problem. And maybe do we need to, like, clarify? Is this what is mistletoe? Is it a plant? What what is it?

Yeah. So it is a plant that's sort of a parasite. I think the dwarf mistletoe are considered more parasites, but they're still hemiparasitic. So they these are plants that they're they're feeding off, they're growing on trees, they're feeding off trees, but they still have leaves and they're still going to photosynthesize. They still make some of their own energy.

So when a seed lands on a plant, a tree, usually The bears are primarily are gonna be eaten by birds. Some mammals will eat them too. And the seeds are covered in a sticky substance called vissin. And when we lived in Florida, we had an oak tree by our driveway that had mistletoe in it. They get knocked out every once in a while in storms.

And I don't know if birds are pooping on our car or if the berries fall enough. The stuff is incredibly sticky and hard to get out of cars.

But they said the the seeds will even stick to the bird's beak and every like, it'll it'll be stuck on the bird.

Yeah. So it's it's it's very sticky. So then when that that seed lands on a tree, it'll send out a penetration peg structure. It'll kind of drill into the plant. And it'll create a haustorium, which is kind of like roots that will attach to the xylem of the tree, which is going to move up the water and nutrients and stuff.

And it'll basically that tree then kind of becomes the root of that mustel. So it's going to start drawing off water and nutrients from that tree. And healthy trees, it's not going to kill you. You may get some dieback from the point where it's attached on because it's stealing so many of the water and nutrients and stuff. So it's

And it gets

So it's acting like a parasite because it's drawing water nutrients, but since it's still producing its own food, it's still photosynthesizing, it's hemiparasitic.

That that makes sense then because so it it it penetrates into the the xylem, as Ken mentioned. And and trees, they have really two conductive tissues. We have xylem and we have phloem. And I always remembered that the xylem moves water nutrients from the soil up the tree from and then phloem moves the the carbohydrates and things from photosynthesis down the tree because xy high and phlo low. And the the mistletoe is targeting the xylem tissue, not necessarily the phloem tissue.

Because phloem, that is photosynthesis stuff. Xylem, that is water nutrients from the soil. And so that that's what it's going at after with with its root system, the what you call them? Austorium. Austorium.

Austorium.

Sure. You remember? I imported a xylem up, flow them down.

Yeah. I nope. I already forgot that. What? Xy high, flow low.

So and and and it kinda creates this witch's broom effect. And a witch's broom, the definition of that, I suppose, it's kind of like a a genetic mutation in the in the plant that creates all this scraggly, twiggy dense growth, which can be desirable in some cases. So if that is the actual tree that is doing the witch's broom, you know, like a a blue spruce, well, they'll cut that part of the tree off and they'll take cuttings off of that, and they'll grow a little bird's nest blue spruce from it. That's a witch's broom and and people can make lots of money off of that stuff. And there's been cases where I have seen I think it was a bald cypress somewhere in Southern Illinois, and it looked like a witch's broom of the bald cypress.

It was growing like the trunk was growing up and the branch was coming out right in that that crotch angle between the two, there was this little shrub thing. And we all got super excited because we thought a witch's broom of a bald cypress, if we could get cuttings of that and propagate it, we could get these miniature little Christmas tree like bald cypresses and sell that and retire before we even graduate from college. It would be great. Turns out, it wasn't that. It was a totally another a different plan.

It was too high up for us to see what it was. I'm guessing it might have been mistletoe though. It might be possible. I don't know if it it goes after bald cypress, but it was not bald cypress because it it bald cypress has a needled leaf and this was a more of a broader leaf shape. So possible it was a mistletoe.

Yeah. I don't know if the the American oh, whatever you wanna call it. I've never I haven't admittedly searched for all the so to speak. But I think I've seen it protect 60 fifty, sixty species like oak, Willows, Sycamore, maple, a lot the hardwood type trees. Yeah.

And and it could also very well have been bush honeysuckle because I have seen that darn shrub grow in a rotted out portion of a of a tree before. So up in the air. So it could also have been just a a honeysuckle berry, a bird deposited up up in the canopy. So, Ken, we maybe focused a little bit too much on the the negative aspect of mistletoe. There are some good things about this plan.

And when reading a lot of these resources, the ecology associated with animals, other plants that actually benefit from mistletoe being part of that ecosystem, There's quite a bit. There's a lot of research on this. I guess, what would you say is would be a good aspect of mistletoe? What good does it do for our environment or our our animals?

I think there's there's several different things. So you've got wildlife habit potentially. So we've got birds that may nest in it because you've got this as kind of shrubby in there, which is gonna have kind of structure a lot of birds want. I think it was somewhere west I think it was Oregon somewhere. They found out like 64% of Cooper's Hawk nests were actually in mistletoe.

So some of these raptors are preferring mistletoe trees with mistletoe in it to build their nests. And I'm sure other birds would be too. Food source for birds, there are mistletoe bird species that are specialists on mistletoe. I'm not sure about how much in North America, but around the world there are birds that specialize on that. I think in North America I have seen like Mourning Doves and Robins and other birds like that will feed on the berries, so potential food source for them.

You've got pollinators. These plants are going to bloom. So you've got flower nectar nectar and pollen resources that those flowers are providing to pollinators. And that could be earlier in the year too. Other things may not be blooming depending on where you're at and the species of mistletoe as well.

And again, in some we get into South America and stuff like that, you've got brightly colored flowers. I think it's references to hummingbirds feeding on them and stuff. So you've got that whole spectrum there of potpainers feeding on that. You've got specialist insects on mistletoe, so the American mistletoe, the great purple hairstreak. The larvae only feed on on that species of mistletoe.

So don't have that mistletoe. You don't have that butterfly. And again, there's others around the world, but, you know, specifically in North America, we've got that one. I don't think that ranges all the way up to Illinois. But it could potentially because we do have that species of mistletoe in Illinois.

And then one cool thing I read about so this is some research done in Australia. So since mistletoes are evergreen and they're not you know, when we think of a lot of our deciduous trees, when they drop their leaves, they try to pull in a lot of those nutrients from the leaves before they drop them to conserve that. Mistletows don't do that. When they drop their leaves, they just drop them because they can just steal those nutrients back from the tree. So when they're dropping those leaves, they're returning a lot of those nutrients back to the soil, particularly phosphorus and potassium, which may help build soils.

And then you've got insects that would potentially be feeding on that. So in this research they did in Australia, this was in eucalyptus woodlands. And these areas didn't have particularly good soils. So whether or not this plays out in areas that have better soil, but they found that you have more plant growth and stuff in these areas that had mistletoe compared to those where they removed all the mistletoe. You also had more species diversity.

I think in the areas where they removed the mistletoe they lost a lot of animals, mammals and stuff that were feeding on insects. They theorized that those insects were feeding on those leaves and stuff. So I guess just increasing the diversity in Australia. I would assume it probably hold true in a lot of other places as well.

You know, and and humans, we really we've again, this is considered a pest for a lot of industries in timber, horticulture, especially out west in in The United States. And this what we and often mistletoe has been considered kind of like this, you know, it's a parasite. Bottom of the barrel kind of thing. Not a big deal if it's there, not a and so on and so forth. So we can probably get rid of it.

No one would notice. But a lot of the articles that that you found, Ken, are arguing and pointed to mistletoe as this is a keystone species. This thing is showing, like, this is a healthy ecosystem. It takes maybe a a uniform stand of timber of it's, like, maybe all one or two species, and it creates these little pockets where other animals, other birds, other insects can inhabit. And so it actually increases species diversity.

And when you lose mistletoe from that system, those species vanish. And so what we once thought of as a just kind of a throwaway plant, now potentially, this is this is on top. This is the keystone species of of ecosystem.

It's it's funny how everything connects with each other.

So we how nature does that.

And there are parts of the world where they've got most of those species that are endangered. So they actually are actively trying to conserve and increase populations, which some people may find crazy, but Yeah. It is an important species in in places.

Yep. I mean, I like spiders. And that's just a crazy notion for some folks. Spiders are good. Mistletoe, it can be good.

Yeah. And I think, you know, we've we've talked primarily about, you know, woody plants, but I've I've seen references where they'll get on cactus and stuff. I think maybe even orchids. One paper they talked about mistletoe's infecting other mistletoe's. And then sometimes mistletoe's infecting mistletoe's that are infecting mistletoe's.

So you've got three three levels there. So it's

It's a mistletoe exception. Yes. I love that. Oh, man. So when it comes to the ecosystem services, is there I I guess this kind of dives into control, which we I wanted to talk about next.

It it talked a little bit about fires, some of the wildfires and how that that patchwork that's created by maybe thinning out some of the trees throughout the forest can actually lessen some of the intensity of those wildfires out west. So I I I guess that that's just another maybe added benefit that that mistletoe might create in in kind of thinning out or opening up a little bit of a dense canopy situation.

Yeah. Think anytime you have open open spots in the forest, things move in and

Mhmm.

Then you go through sec secession and all of that. So

Oh, yeah. And and and here in Illinois, when you have an open space, it's maples that seem to fill it in whether you want them to or not. A lot of times, we don't. Yes. And I know people love maples.

They're great trees. I just I just have too many of them. Yeah.

Unless people have too many of them.

Yep. Yep. Okay. So mistletoe. Let's say if somebody's listening and and the the range for the American mistletoe, we are seeing that creep up in the Central Illinois, probably mostly in Southern Illinois, maybe creeping up in the Central Illinois these days.

If somebody wants to control it, can they kill it without hurting the tree that it's growing on? Or is it forever like some type of sci fi horror movie? Is it like ingrained into the nervous system, which trees don't have? But is it ingrained into that that tree's vascular system and there's no saving it?

Yeah. So this isn't gonna be like a normal coat of weed. You're not going to go out and spray this because anything that you spray on that that mistletoe, because it's plugged into the vascular system of that tree, it's going to get moved down into that tree. So you're not going out and getting the glyphosate and spraying it because that's going to get into your tree as well. If you just break off that mistletoe from the tree, you just break it off from a branch, again, austereum is attached to it.

It's infiltrated that tree so it can just re sprout from there. So if you really want to get rid of it, you've got to prune it out. Prune the entire branch out to remove that mistletoe. And depending on how big the the branch is, that may or may not be beneficial. You know, if you leave a large wound, that could cause just as many problems as as leaving that mistletoe.

And I don't think admittedly, I'm not an expert on mistletoe, but I don't think at least in Illinois, mistletoe is really that big of a concern. We'd really, really want to to control it. I'd be excited if I had it be a good conversation starter.

I think that would be neat. Yeah. I'd be like, yeah. See that tree? It's got mistletoe in it.

I would be excited to show that to people. And then they would walk by and just say, I've never met you, sir. Please stop talking to me. I'm just trying to walk by your house.

Yeah. I'm never coming to this guy's house again.

I'm not walking in this neighborhood anymore. Now one of the techniques that I've heard that they've done out west to help them control mistletoe and some of their timber stands, which sounds terrible, is just they clear cut everything. They just wipe out, you know, the wide wide area. And because the the if there's no mistletoe there, there's no sticky berries to land in the tree branches, well, then you have a fresh slate, regrow your timber stand, you know, thirty, forty years, you'll get a a harvest of some straight trunked trees, and that's it. So but that that sounds a little extreme to just clear cut an area to to try to eradicate mistletoe.

Till birds come in and poop it. That's your trees and that's Yep. That's right back there.

There you go. Yes. Like, thought I got rid of it by by cutting everything down twenty years ago. Life will find a way. Exactly.

Yep. Jurassic Park. That's right. Doctor Ian Malcolm. I've referenced as many of his papers in the past.

Well, have we hit everything about the mistletoe?

Unless you wanna talk about the kissing. Like, actually because I think the I think when you're, you know, technically when you kiss, you're supposed to pick a berry off every time you kiss under it. And then when the berries are gone, the kissing is over. You're not supposed to kiss under it anymore.

Hang on. I don't know this process. Guess I didn't grow up. Didn't grow up with mistletoe in the house. I did.

So hang on. And what alright. Re redescribe this process of I have to do you you don't eat them, do you? They'll kill you.

Yeah. Berries so the berries are toxic.

Don't eat them.

Yeah. Well, we can get into after this, can get into the berries and what they're used for. Okay. So so my understanding and again, I didn't didn't do this growing up, is that when you're you hang mistletoe, mistletoe has got the berries on it. So when you're underneath of it, you know, you give a kiss or get a kiss and you pull off a berry.

As long as there's berries under that mistletoe,

you can still kiss. Once the berries are gone, there's no more kissing. It relates to Frigg's tears. She's giving out love. Ah, it makes more sense now.

Interesting. Okay. Alright. Well, I don't think I'm gonna do that. I have kids.

They're not that smart when it comes to putting things in their mouth. It's Neither are my cats.

Get some fake stuff.

They might have to get some fake stuff. And I think the cats would still eat it. The kids might try too also. Okay. So, Barry, is what are are is mistletoe used for anything in the human world?

I mean, birds eat it, the berries. Do we use it at all?

Yeah. So, you know, the the berries and mistletoe are toxic, particularly the European mistletoe, which is I think what most people are or most of these traditions are built around is European. American is too. It's less toxic, but it's still not something you want use. It's still toxic.

Yeah.

But it has been used, I think it's the European and some of the chemicals from it and treating cancers and stuff. So that's not approved in The United States, but it is used in Europe. And so don't go out and eat it because the dosage isn't going be right. There's going to be other stuff in there that you don't want to be ingesting and stuff. So there

are there is some More problems.

Yeah. There are some some modern day medicinal uses. And I think in ancient times it was used as a medicinal as well for for various different ailments. I think with the the druids, I think one of the things they would do with the druids, they would go up and was that they cut it down with a golden sickle. Mhmm.

They sacrificed two white bulls to the gods, which I found also found references to originally it may have been humans, but that's the bulls got put in there when the Romans outlawed human sacrifice, once they conquered that part of the world. And they would make an elixir with a mistletoe, which would cure infertility as well as act as an antidote to all poisons. So

Which it's technically a poison in of itself.

Yeah. The mistletoe poison, not the other poison.

That's right. You don't have to worry about any of that fertility stuff. Yeah. Mhmm. Yeah.

Oh, man.

All kinds of crazy stuff.

That is crazy stuff. Interesting that things humans we used to do, but sometimes still do. Yeah.

They are somewhere that most of the mistletoe that's harvested. I've never seen mistletoe for sale, personally. And I don't know how widely available it is nowadays. I think maybe a hundred years ago it was a little more common. I think I saw somewhere in Oklahoma, Texas, that part of the country is where most of the mistletoe is harvested and sold.

And that mistletoe is also the floral emblem of Oklahoma.

It is. It's on their seal, I think.

I don't know how a floral emblem because they have a state flower, Mhmm. Which is something different. So I'm not sure what exactly floral emblem is.

That's something else we'll have to investigate. Well, that was a lot of great information about mistletoe. Help you at your upcoming holiday trivia night. Hopefully, they have a category all about mistletoe. If you wanna learn more about poinsettias, we talked about that last week.

We had a great resource also for this article. I'll go ahead and link to that in the show notes below as well. It's titled mistletoe's pathology, systematics, ecology, and management. So we'll we'll link to that below. And, yeah, this this should be a lot of fun reading for you if you wanna learn more about mistletoe.

Well, the Good Grind podcast is a production of University of Illinois Extension, edited this week by me, Chris Enroth. A special thank you to Ken for doing all of the hard work behind these episodes, researching plants, finding fun, interesting articles to share with everybody. So thank you, Ken. Once again, do coming in saving the day this week.

You're welcome. Start it up again for next week's.

Oh, we shall do this again next week. We're going to be talking about holiday spices. I'll do my best to limit my talk about ginger as much as I can because we've probably beaten that that horse enough. So, yeah, we'll we'll we'll stick with some of the other holiday spices. How's that sound?

Yeah. Sounds good.

Alright. Well, listeners, thank you for doing what you do best and that is listening. Or if you're watching this on YouTube watching, and as always, keep on growing.