From the Vault: Tumbleweeds, Part 1

Robert Lamb and I'm Joe McCormick. Like many of you out there, I've been familiar with with tumbleweeds for a while, but almost almost exclusively as just this um sort of mundane symbol of the American West, right, you know, men, Mainly it's this type of thing you see popping up an old westerns or perhaps more to the point, old

cartoons inspired by old Westerns. Anytime you need the audience to understand, this place is is desolate, this place is in the American desert, or this place is a ghost town. What do you do? You have the old tumbleweed roll by, Yeah, tumbleweed means nothing's going on. In fact, I think it's even a common gift. Right. You can meme a tumbleweed if you are to indicate this thread has died or or you know, nobody's got anything to say. Yeah, there's

nobody in here. This is It comes to represent like not only desolation, but also uh, emptiness and tedium. You know, it's just in boredom. It's like this, this place is empty. This place there's nothing going on. This is the domain of tumbleweeds. And therefore it's easy to think, well, tumbleweeds themselves are boring tumbleweeds. Uh, there's nothing going on with tumble weeds. There's It's not the kind of thing you could do a two part series on for a podcast.

Oh but you would be wrong, yes, yes, uh and uh and hopefully we will we will prove that in uh, in this pair of episodes that we're gonna be doing. Um. But but before just a couple of weeks ago, I was very much of the mind the tumbleweeds. They they pop up in movies sometimes a lot of times they look fake. Um. Yeah, for we were actually looking at some clips prior to recording these. You know, does this look like a real tumbleweed or a fake tumbleweed. Um,

And I wasn't always in a good place to judge this. Well. I think one way in which movie tumbleweeds often fall short is in size, just the size shown, because the tumbleweed in the movie it's always pretty much basketball sized. It's very round, or maybe you could say like turkey sized. You know, it's like a good Thanksgiving turkey, but it's made out of twigs. Now, obviously, tumbleweeds can vary in size and reality, and we'll we'll explain more about that

as we go on. But you know, a lot of real tumbleweeds I've seen, especially in some of the more dramatic uble weed footage where where humanity is really doing battle with with tumbleweeds. Uh, they get big, you know, they're more in the like beach ball to bean bag chair range. Oh absolutely, yeah, you know, thinking about the

cinematic ones. Yeah, a lot of the times when you see a kind of essentially a fake looking kumble weed and obvious plant, a plant that is it self a plant, um, it will be that beach ball or turkey sized, uh, tumbleweed just big enough to where it is amusing, but not a threat. Uh, it'll just kind of be, you know,

lazily rolling by in the background. And uh, one film that that I was looking at it was pretty interesting because you can see both examples of this, and that's the film The Petrified Forest starring Leslie Howard, Betty Davis, and Humphrey Bogart, which in and of itself is a tremendous film. But some of it is is obviously on more of a set or a sound stage, and other bits of it are filmed outdoors. Uh, perhaps in actual Arizona or at least somewhere in California that that you know,

fit the bill. Yeah, yeah, And in the location shot, in fact, there's an early location shot where you see Leslie Howard's character walking down the street there and there's a fair sized tumbleweed that that comes in at a at a pretty swift pace. I don't know if they filmed it in during an actual windstorm or they just have some you know, some big fans going. But uh, there's a moment there where I when I was rewatching and I'm like, oh, jeez, I hope this doesn't hit

Leslie Howard. That would uh you know that that that wouldn't be very becoming of such a suave character. Well, isn't the beginning premise of the film that he has traveled out west in order to maybe commit suicide. So is it possible that he wanted suicide by tumbleweed? I don't know how romantic would that be. Uh? Yeah, I think he says that he he's hoping to one day

see the Pacific Ocean and perhaps drowned in it. But but I can't imagine saying I hoped one day too to uh run across the six feet tumbleweed and be demolished by it. I hope one day to to be absorbed by a sea of thorns. Yeah. So yeah, to to get back to the to the point here. Yeah,

these tumbleweeds can get rather large. And I never really realized this before until this holiday season, this uh that we've just gone through because this year or this previous year rather just after Christmas, my family we found ourselves um driving south from Phoenix to Tucson, Arizona, and then west towards Las Cruces before cutting up to Albuquerque and then Santa Fe and um, and we were doing this because we originally are going to take a northern route

through Flagstaff, but winter weather forced us to pivot. So here we are, Uh, we're going on Interstate ten between Tucson and Las Crucis. And what during my stretch of the driving, we begin to enter this uh, this this this uh you know that you know, we're in the desert, is you know, desolate. We get these advisories about possible you know, wind possible, uh, dust storms and uh and

then I begin to see the first tumbleweeds. Uh. And you know, I've been going out west for a while now, and I don't think I'd ever really seen a tumbleweed in action. Maybe i'd maybe i'd seen one small like turkey basketball size one. But this was the first time I started seeing some real bad boys, some real monsters rolling around. Uh. For first of all, at the you know, sort of the side of the road or sometimes like

stuck up against a fence. But then eventually, uh, they're they're crossing the road, they're being blown across the the highway. And it's quite alarming because again, some of these are are huge. There we were we were commenting at the time, perhaps overreacting that they look like they're the know, about half the size of a Volkswagen. Did you hit one? Oh? Yes, yeah. Eventually let's started hitting them and they explode. Yeah, they kind of or it's kind of like, um, it's like frosted,

not frosted of what were they? Yeah, but not the many ones, the big ones. Oh yeah, Okay, it's like a shredded wheat, like shredded many wheat. Of the shredded wheat hitting the front of your car, they just kind of, uh yeah, crumple and implode and um, part of it gets stuck under the vehicle. But it's alarming because they're so big in volume at the size at the time.

I don't know why I thought of it this way, but I was imagining it's like running into a ball of about five thousand tooth brushes and toothpicks, all loosely taped together. Yeah. Yeah, and it's it's like that. And yeah, you're seeing them slam into other vehicles in the the opposing side of the highway. I'm watching them just slam into the fronts of tractor trailer rigs and and it's weird to watch them because on one hand, there there's something about the tumble weed moving around that is kind

of comical. There's something absurd about it, and so I'm kind of freaking out about the driving of My wife is just like cracking up laughing at these things in the seat next to me, and um. And then the other thing is the way that they're you know, they're

they're not perfect spheres. Uh, They're not perfectly round. They have this kind of oblong shape to them, so they kind of tumble and bounce, and especially with the you know, the uncertainty of the wind and also the aerodynamics of the high speed traffic, the way that they behave kind of comes to to mimic that of an animal. You're trying to figure out what's it gonna do? Is it gonna cross, is it not gonna cross? Is it gonna

halfway cross? And then change direction? And so all of this adds up to this this anxiety I was feeling about these tumbleweeds because I'm trying to to to figure out what they're going to do and if I'm going to hit them, and then I have to make sure I'm not going to swerve and make the situation worse. Well, so with us talking like this, I immediately wonder if it's like if it's like us also talking about trying

to drive in snow. I don't know if you've seen the stuff on the internet where anybody who lives up north makes fun of people from the south. You're like, you know, there's like an inch of snow on the ground and suddenly nobody can drive. Yeah. I imagine that there are some some desert dwellers out there who are who are having a laugh at um at at how we're talking about this here, And I mean they're probably

used to it. Uh yeah, I just I don't think i'd ever been down there or and I wasn't in the right place at the right time to encounter like full blown literally full blown tumbleweed season. And I was I was actually wondering, why are there no signs advising tourists about this, Like they're warning us about what to do during the dust storm, But how about it like don't swerve, just go ahead and hit the tumbleweed, you know,

some sort of a poster to that effect. Anyway, I afterwards, I started looking around because I was curious, Well, you know, does this ever get out of hand or is this just something where if you're if you live around at you're used to it. Well, uh, I did some research online.

I started running across news stories with headlines featuring things like tumbleweed nightmares from as recently as last month, in which winds basically blocked certain New Mexico roads with tumbleweeds, or a NBC headline quote thirty foot tumbleweed pile up traps, cars, semi trucks on Washington Highway or another one. This this

was quite impressive. Tumbleweeds bear a New Mexico town. And if you start looking up footage or images of some of this um it's it's not as much of an exaggeration as as you think, like you're looking at a two story like suburban homes and the tumble weeds, which again you're talking about tumbleweeds that can reach, you know, sometimes like six feet in diameter. They're piling up, They're

reaching the second floor of the house. Yeah, piled up like heavy snow drifts, except probably even more difficult to deal with than snow, right because snow, I mean you can at least shovel out of the way. I don't know if I could say easily, but to some degree easily.

Tumbleweeds are notoriously difficult to handle and deal with. I think because of their size and their shape and the composition, like the thorny nous of them, it's difficult to just grab them because they're usually thorny and and in some way repel your flesh and uh. It's also difficult to to sort of scoop them out of the way because they tend to break. Yeah. With snow, like, one of the great things about snow is that even if you don't shovel it um, usually what's gonna happen is it's

gonna melt. Right, the sun is gonna come out, temperatures are gonna rise, that snow is gonna melt. The tumbleweed is not going to melt. The tumbleweeds a mask against the side of your house might not distribute on their own, and they might catch on fire, might catch on fire, Yeah, because they're basically they're dried out, lifeless, brittle um vegetation. So they're they're they're a fire hazard. They're a legitimate fire hazard clumped up against the side of your house,

so you've got to get rid of them. Or if they're not again, if they're not against the side of your house, then they're perhaps blocking the road. Uh. They can also cause other issues, you know, they build up against fences. They can interfere with with drainage systems. M because again, a lot of the environments we're talking about here are very dry most of the year, but then there will be a deluge and during that time you

need to have sufficient drainage systems in place. You don't need those drainage systems and canals, etcetera clogged with old tumbleweeds. They can also interfere with irrigation systems. They can they can cause a huge mess, and they do cause traffic accidents. Um, I'm read. I was reading about one in Jadito Wash that was apparently so impressive that the Arizona Daily Press did a ten year anniversary story about the incident, and I included a photo from the story in our notes here, Joe,

it does look quite impressive. You ever, like comb a shedding dog and end up with all these clumps of hair that you need to get rid of at the end. But then now imagine that, but it's twenty ft high. Yeah, it's like like Clifford the Big Red Dog Marmaduke sized uh pile of of of shavings here now, like you were saying, Yeah, it's difficult to clean all this stuff up. What do you have to do? You have to get a work crew out there. They've got to to gather

these materials up. You've got to put them into vehicles, uh, and and take them somewhere, take them away, and they're mostly air, so you end up like really filling up a vehicle. But then you know the weight volume isn't there, so uh, you know, you start doing the math on on you know, the cost of labor, the cost of materials, the cost of transportation, and and the cost end up really skyrocketing for the various counties and towns and cities that have to engage in this kind of cleanup effort.

One of the articles we were both reading for this episode is a PBS article about tumbleweeds by an author named Gabriella Kiros, but citing information from somebody named Ariel of Vario, a deputy agricultural commissioner at the county's Weed Abatement Division in Lancaster, calif Borno. Ciros writes, quote in the cities of Palmdale and Lancaster, tumbleweeds are such a big problem that Los Angeles county spends a hundred thousand to a hundred and fifty thousand dollars yearly mowing and

chipping dried out Russian thistle. That's a name of one specific dominant species of tumbleweed in vacant lots and abandoned agricultural fields before they can tumble away. So this is above a hundred thousand dollars a year of a problem for one county, I mean big county. But uh, every year,

it's enough to make you wonder. Um, you know, there's got to be a better way, right, It's got to be some sort of technological improvement, uh, that that we could make that would uh, that would improve this situation. Uh and uh And indeed I found evidence of a of a really promising and and frightening looking project that I'm not sure ever really quite got off the ground. But I to read verbatim from this n l A Times article by Eddie Pell's go for it all right,

There we go Los Cruces, New Mexico. It looks like a contraption straight out of a Stephen King novel, huge metal spoke, squirreling away, shredding everything in its path. But the invention from New Mexico State University's Advanced Manufacturing Center is out only to mow down the bane of the West, the ever present tumbleweed. So you shared video of this mangler with me, and it does look like a beast. Yeah.

I found this this archived video that was put out I think by the by a New Mexico State University UM or perhaps the State Highway Department. I forget which, but it was it was all about this this promising new project, and it included footage of the prototype for this that the invention we're talking about is the tumbleweed crumbler.

It was developed via a forty contract at the time to New Mexico State University from the State Highway Department develop a better way of collecting and shredding the time buble weeds. And the prototype was essentially a pair of rotating, like inwardly rotating metal spokes hooked at the front of

a snow plow truck. Um. Yeah, so it's like drum barrels imagine that are sort of rolling inward as if you know, to roll things into the gap between them, which is pretty small, and that it's got spikes sticking out of the drums. Uh. And There's a really excellent part of the video where a guy is standing right in front of it while it's running, kind of feeding tumbleweeds into it, and we were thinking, like, oh, is he going to reach in there to try to clear

out a jam by hand? Yeah, it's gonna be like one of those that like shake hands with dangerous safety videos. It just looks very unsafe and and I don't, I don't know. I may the guitar twine comes in. Johnny thought he could save time because the I mean it's terrifying, but it also looks really effective. They show it, uh

like running into mounds of tumbleweeds. These uh, these wheels with the with the spikes on them, they grind up these these tumbleweeds and then the ground up remnants are like sucked up and shot into the back of the

snowplow truck. So, uh, you know, this seems like it seems like it would it would have been a great fix because first of all, you have the snowplow trucks anyway that are being used during you know, parts of the year to to deal with keeping the roads clear, and then snowplow trucks without this kind of spike contraction are apparently sometimes used to clear the roads of tumbleweeds anyway, though of course they're just mostly pushing them out of

the way and not really you know, not collecting them. So it seems like this would have been a cool way to to deal with the problem. But so are these machines day rigur Now, No, I don't think they are. That's the thing, you know, you you see, uh, you see an article like this, and you see I see footage like this, and again this was ninety six and as far as I can tell this this ended up not really going too much more beyond the prototype phase in the video they're talking about they're going on to

another as a development. And I don't know. Maybe I couldn't find an answer as to why exactly they didn't go with this. Maybe it just came down to something as mundane as uh, you know, the money or politics, uh, cost effective or something. Maybe it just wasn't cost effective. I don't know, maybe it was too dangerous. I have no no way of knowing, and I wasn't able to find out. But this seems to be a trend with a lot of issues related to the problem of tumble weeds,

particularly in the United States. I kept running across UH promising sounding scientific solutions UH from years past, solutions that in many cases may still be in development, but but but have not reached that point where someone is out there saying, yes, this is the thing we're actually doing tumble weeds, watch out because we're coming. Though some of these solutions do get more sci fi than the mangler. Yes, yes, thank all, Right, well, I guess it's worth explaining it

this point. What are tumbleweeds? Uh? And I think the most important point to say the beginning is that technically tumbleweed is not a single species of plant. Tumbleweed is a common morphological feature of a number of different species of plants spread out across different families. Though in the American context, there is one single species in the in the amaranth family that tumbleweed most often refers to, but it's by no means the only one, and we'll talk

more about that species in particular later. But the broader category of features of a tumbleweed is this. So a tumbleweed is the above ground structure of a plant which at maturity dries up and snaps away from the roots. Structure and then is blown around by the wind, scattering seeds as it goes. Yeah, it's sometimes referred to as a detachable diaspore. Yeah. And and a diaspore is basically any seed and other structure that helps the seed spread.

So die spore could include like say, a little parachute like thing that catches the wind, or it could include like a fruit to that you know that an animal would eat. It's the thing around the seed that helps the seed get where it's going. Yeah, but in this case it's pretty much the entire above ground part of

the plant. Uh. And So there are variations between different species, but in most cases you can picture, for a tumbleweed, a bush like plant that becomes very brittle and dry and has a big tangle of different stem segments, and eventually it breaks off at the roots at roughly the place where the stem meets the ground, and then it rolls around on the planes, driven driven on the wind,

like a giant inflatable ball. Now you might think, Okay, most plants don't break off at the place where they meet the ground and then get their bodies blown around, dead and dry by the wind, So why do tumble needs do that? Well, Actually, the answer is similar to the answer to the question why are fruits delicious? Uh. The the answer is it's for seed dispersal, meaning the transportation of seeds and thus the next generation of plants

away from the parent and UH. A lot of plant species actually spend a great effort at seed dispersal, and there are a host of different strategies available. So, for example, there is animal dispersal. So you can think of the seeds of edible fruits. The fruit is tasty and dense and calories, so animals want to eat it. The animal will be attracted to the fruit, they'll nom nom, they'll swallow it, and then they will travel elsewhere on their their wings or their legs, and then they will defecate

and deposit the seeds in a new home. But that's not the only method of animal dispersal. There are also the burrs that cling to the fur of mammals that that brush up against the parent plant. Uh. You know, I don't know if if you've got pets that burr magnets like my dog is. But you know, sometimes Charlie will will get into some bushes and then when he when he comes out, it's a problem. He has probably like you know, a thousand of these things stuck to him,

and and there are a bunch more that there. For example, there is a whole class of of diaspores that are spread specifically by ants that you know that they have specific relationships with ants that will maybe bury them underground in a way that's preferable to to the plant. But there's also wind dispersal, So you can think of the seeds of dandelions. They contain a natural parachute, like a structure that catches the breeze and allows the seed to be picked up by the wind and blown to new lands.

There's water dispersal. Coconuts are a great example here. They float on the water and allow currents to carry them to New German nation sites. There's gravity dispersal, that's what it sounds like. There's explosive dispersal. That one's fun. Yeah, yeah, bursting pods and so forth. So there are a number of from methods UH, and there are some primary reasons that a plant would want to disperse its seeds to

get the seeds away from the parent plant. One idea is that doing this UH reduces competition between the seed and the parent plant. And with other nearby adult plants. So, just like animals, plants need access to resources. And uh one example here would be sunlight. Plants need sunlight in order to power photosynthesis. But if they fall straight down off of the parent this could limit them right because they could be trying to grow in the shadow of

the adult plant. And you can imagine other competitions for nutrients in the soil, for water and so forth. So one reason seeds might be dispersed is that the is that it allows the parent plant and the offspring to grow separately without competing with one another for access to

the same resources. You know that that does make me think of the old thing the apple does and fall far from the tree, But that's saying really kind of misses the point because it's not the The apple is not supposed to just fall off the tree and remain there, and then the seeds are going to end up in the soil right there beside the parent tree. Like the idea is that this is animal dispersal, that those seeds are in this lovely, delicious apple that's going to be

consumed or carried off by some other creature. That's a very good point. If the apple stays too close to the tree. That could be really bad for the young apple right or the young apple tree I guess um. But then there are other reasons. So that's just one possible motivation in the evolutionary sense. Other evolutionary motivations for seed dispersal would be saying, limiting bad things that can happen to young plants when they tend to be densely

congregated around the parent plant. Uh So, these bad things could include contagion, could include the you know, the spreading of pathogens that would spread among densely congregated plant, or the harvesting of predators. So if say seeds are potentially edible and they all fall in one place right around the parent, this often results in say an animal that would eat those seeds. It would eat those young plants, the seedlings, uh coming, gobbling them all up at one

time in one big buffet. But if they spread out all over the place, the risks of things like pathogens and predators are reduced. And then other motivations could be things like colonization of new areas without competition. So you might want a way to spread your your offspring plants to areas that don't really have any other plants in them right now, you know, just kind of some bare

ground if it can be located. And in the cases of tumbleweeds in particular, that often is located because tumbleweeds can grow in areas that many other plants can't tolerate or haven't been able to take root in yet. And that's going to be key moving forward, So keep that in mind, right, Uh and uh. But another thing might be that see weeds would be dispersed so that they could target a specific germination spot to where the plant is likely to thrive. And you can interpret that in

a couple of ways. For example, some animal dispersal would mean that the seed ends up either buried in the ground or maybe surrounded by dung which can protect it and provide other benefits. Or in other cases, uh, this might be methods of dispersal aimed at getting the seed to a certain kind of landscape or environment. Yeah, and I guess one thing to keep in mind. It kind of goes back to the whole day about the idea

about the apple falling far from the tree. It's not about where the apple initially falls, it's about where the seeds end up and with the tumble weed, it's actually quite similar. It's not about it's not about really where the tumble weed ultimately goes. It's about the seeds it drops along the way, that's right. So if you apply what we've been talking about to the tumbleweed in particular,

how does it disperse its seeds? Generally, what what the detachable diaspore of a tumbleweed plant does is dry up with a bunch of seeds in it, and then it will be blown about by the wind, dropping seeds as it goes, because it will be kind of dry and brittle, so it bounces over the landscape, uh, sort of degrading and breaking apart as it as it blows around, and it will drop seeds intermittently, so all over the place you get. You get vast seed dispersal with this method,

and thousands of seeds. Yeah, yeah, totally. And also if there are any seeds left in the tumbleweed when it reaches its final destination, whatever that is, I mean, I guess there probably usually are some seeds still left in it. Uh, it can it can try to germinate from wherever it comes to rest, especially if it finds a water source. If it happens to land in a place with moisture, yes, But one of the interesting things to keep in mind is that, again, this is a plant that does extremely

well and barren environments. Uh So, like an abandoned agricultural site. Oh that's that's that's pristine for the tumbleweed. You know, a vacant lot. Yes, it wants to get in there. But one of the things about say, tumbleweeds accumulating in a well irrigated yard is that I've I've read that those those tumbleweed seeds if they land there, and they're not going to really be able to compete with the

grass that's growing there. So yeah, this is ultimately a plant that is at its best uh in the worst of environments, at least from uh you know, from from from a typical human perspective, in the worst of environments, or in environments that have for some reason been cleared of their natural vegetation, which often happens in the case of human development. Yeah, and I think it's worth this is something that I saw pointed out in a couple

of different sources. It's easy to get to get in this mind because again, tumbleweeds and we'll discuss more about this. You know, they're they're a pest there there and there there. It's it's a problem that people having to deal with. But you can't just look at the tumbleweed like a disease. You also have to look at the tumbleweed as a symptom of land degregation degradation. Yeah yeah, so uh, let's talk about the life cycle just a little bit here. So, um, so,

what happens once that seed lands in just the right spot. Well, they don't need much water at all to start growing, and they have this kind of like screw like shape. They're they're kind of interesting to see the close ups of the seed. And then when they start growing, they start out looking like just blades of grass. They have kind of like a pinkish uh, like a white and pinkish um section towards the bottom. They almost look like it almost looks like some sort of weird onion grass

or something. Oh yeah, yeah, Now I want to be clear at this point, we're talking about one species of tumbleweed in particular, the one that that Americans usually mean when they say tumbleweeds. So now we've narrowed it from the broader class of tumbleweed structures to the plant people are usually calling tumbleweed, which is known as Calli tregas or sell Sola tregas, or more commonly prickly Russian thistle.

But yeah, that's the one we're talking about now. And yeah, and and I'll get into a fascinating little history lesson about that one in a bit. Yeah. And if you're a singing cowboy, this is the variety you're probably singing about. Yeah, unless you hear like a really uh like you're singing botanist cowboy, and then perhaps you have a more robust um uh you know, lyrical treatment of the whole situation.

But yes, your your description is good. Yeah. So, like usually white and pink lower stem areas branching out into green grass like structures above and in in this young form, you know, this plant doesn't look quite so quite so threatening. You know, it's not thorny yet, it's not dry and brittle yet. And uh and according to the way it looks, in fact, that this this young form can be eaten

by some animals. Yeah, and it it should be noted that the initial leaves here are long, but then these spring leaves eventually fall off and they're replaced by shorter leaves. Each flower contains a fruit that develops into a single seed. But then in the late fall, and and again we're just talking more or less about one variety, you see some some differences depending on the variety of tumbleweed that

you're you're looking at the different species. But during the late fall, they begin to dry out and die, and the wind eventually breaks the dead tumbleweed free of its roots. And as as described in that that PBS source wee we referenced earlier, it's a clean break. Um, it's it's the sort of thing you could compare to like a lizard shedding its tail due to a microscopic layer of cells at the base of the plant called the abscission layer.

Uh so this allows it to just snap off. So the part of the stem that was made to snap clean, it's like the part of the lizard's tail that can that can shake off for autautomy. Yeah, yeah, so it's it's you would be forgiven if you just you know, casually thought, well, you know, it's it's a dry place and these bushes they just get so dry and dead, and then the gets so windy here it just snaps

the bushes off and they rolled around. Um, but no, it's it is that, but it is also a a species that has evolved to take advantage of of this environment and to snap off it just the right place and it just the right time. Now, I saw some wildly different numbers about how many seeds and individual tumbleweed

plant can drop as it rolls around. I assume obviously this varies by species, but even just with reference to Calli tragus or the Russian thistle, I saw people mentioning that, you know, one can drop a few thousand seeds, like maybe two thousand or twenty hundred, and then I saw estimates of like hundreds of thousands, So I really don't know which one is more at the correct end there, Yeah,

I saw tens of thousands. Um. I guess the tacome here is that we need to think of it again, not as like a single seed, but a depositor of many, many seeds. It's not about where the where it goes. It's about the seeds it drops along the way, as it tumbles, as it bounds across the landscape, as it

weaves in and out of traffic and collides with semi trucks. Um, it's just gonna spread out the seeds across the way, and and all the ones that land in just the right spot are going to have a shot at growing into plant, into adult plants themselves. It's one of those evolutionary marvels, which is in fact neither of these things, but kind of strikes you somehow as stupid and genius

at the same time. Yeah, and I think that's that again kind of cuts to the reason that tumbleweeds can be both frightening and impressive in person, but also innately comical. There's just something kind of ridunculous about this large bush bumbling and bouncing across the landscape. So I was curious about the you know, the physics of of this thing. I was like, and my and my wife even brought this up, just like, surely somebody's looked at the physics

of this. So I was looking around and I found a wonderful book by Ralph D. Laurens, a planetary scientist and engineer at the John Hopkins Applied Physics Lab. It's titled Spinning Flight Dynamics of Frisbees, Boomerangs, Samaras and Skipping Stones, And uh, there's a there's only a brief part of the book that really gets into tumbleweeds um and ultimately he ends up talking more about tumbleweed rover designs, which I'll touch on briefly in a minute. But uh, first

I want to read this quote from the book by Lorenz. Quote. It is worth noting that the center of mass of a tumbleweed is generally offset from the geometric center. To what extent this is an inevitable consequence of the dendritic architecture of a plant, in that the branches must converge towards an apex which is linked to the roots system is unclear. It may be that there are dispersal performance

advantages in such a departure from spherical symmetry. Tumbling bouncing rather than rolling, may enhance the shedding of seeds from the plant. That totally makes sense to me. So if it were a more perfectly round dry that were to roll away, it might roll better, but it also might shake. Uh, it might shake seeds loose in a less even way. But by having a kind of oblong or uneven structure, it's always kind of bouncing while it rolls, and with every impact as it bounces it can have a greater

chance of shaking some of those seeds loose. Yeah. Absolutely, And he also points out that that the tumbleweed is naturally porous, so when we look at the air flow, the air flowing not only on and around it and against it, but also through it. Um. And he discusses he discusses most of this in connection again to the tumbleweed rover designs. These are various UH engineering approaches to creating some sort of a you know, a rover or

probe that will work on the UH. Generally we're talking about the surface of another planet or another planetary body of some sort, or a moon or or something. Yeah. Yeah, Mars is often a target here because again we have to remember there is wind on Mars and UH and if we could take advantage of that, uh, that would

be a way to to move a rover across the landscape. UM. So you have various takes on this that are you know, and some are inflatable, some are non inflatable, UM, you know, roughly spherical designs to allow a rover to roll more or less like a tumbleweed. UM. But it sounds like the you know, while this is a promising area of study. The tumbleweed rover nut remains too, you know, remains to

be fully cracked. But a lot of the science around it um I thought was interesting because it kind of helps illustrate what really works about the tumbleweed, the plant as a as an as an evolved solution and as an as as an evolved approach to the landscape, and

what wouldn't work for a probe or a vehicle. So some of the designs do tend towards non smooth surfaces like the real tumble weed, and there have even been some experiments with oblong shapes, but these produced bouncing to acquired kinetic energy, something Lauren's rights is quote not recommended for an attractive vehicle design, and I think that's quite telling again because with it, with these tumbleweed rover designs, we are trying to solve a human vehicle problem, how

to move a thing from one place to another and potentially to other locations, and to control the movement as well. The tumbleweed plant, on the other hand, is not trying to arrive at a destination. It's again all about the journey and that it and it's going to drop its various seeds along the way and bouncing far from being a danger to sensitive cargo and and uh, you know, sensors and whatnot. Uh, this can help free the seeds that need to be dropped and um, you know, and

again naturally, tumbleweed plants are not perfect spheres. They're they're they're vaguely spherical and are I guess more bush shaped than anything, um as opposed to like, you know, ball shape. They're more shaped like a turkey than they are shaped like a beach ball. If if a turkey were likely to be like one to two meters in width and was like getting light enough to be pushed around in the wind. Yeah, they're they're really it's it's really remarkable.

All right. Well, I think it's time to talk a bit about the history of the tumbleweed. And one of the strangest facts about the tumbleweed, this icon of the American West, is that it is not actually native to North America. It's a fairly late arrival. In fact, one of the most common plants categorized as a tumbleweed in the United States today is the one we focused on a good bit already. Uh, known sometimes as callie tregas or previously known as Salsula tregas. The common name again

is prickly Russian thistle. The name gives it away a bit where it actually comes from. This is a species originating in the steps of Eastern Europe and Western Asia, probably around the area of Ukraine. And I found a very interesting description of tumbleweeds in an eight teen fifty two botanical reference book by an English surgeon and botanist named Arthur Henfrey. It's called The Vegetation of Europe Its Conditions and Causes, published by Javan Vorst in eighteen fifty two.

And uh, he gets to talking about tumbleweeds in the section of the book where he's cataloging the plant life of the Russian step. So again you have to imagine that at the time this was written in the eighteen fifties, there was probably no trace of this type of tumbleweed in the United States. But here's what Hinfrey says. In these regions, the wormwoods and thistles grow to a size unknown in the west of Europe. It is said that the thistle bush found where these abound is tall enough

to hide a cossack horseman. The natives call all these rank weeds useless for past year Burian, and with the dry dung of the flocks, this constitutes all the fuel they possess. Oh and I should note, by the way, that while he keeps saying thistle, because that is the common name and what they were classifying at is back then, I think technically in the in the modern botanical sense, the tumbleweeds were referring to are not true thistles. They're

not thistles, but that's what they're called here. So Hanfrey goes on. One curious plant of the thistle tribe has attracted the notice of most travelers, the wind, which, as it is called by the German colonists, or leap the field, as the Russian name may be translated. It forms a large globular mass of light, wiry branches interlaced together, and in autumn decays off at the route, the upper part

drying up. It is then at the mercy of the autumn blast, and it is said that thousands of them may sometimes be seen coursing over the plane, rolling, dancing, and leaping over the slight inequalities, often looking at a distance like a troop of wild horses. It is not uncommon for twenty or thirty to be come entangled into a mass and then roll away, as Mr Cole says, quote like a huge giant in his seven League boots.

Oh my goodness, yeah, this is this is exactly what I was saying on the highway a couple of weeks ago, because sometimes you would see two that were I saw at one point two of them that were bound together. And this monstrosity was what jumped in front of a semitruck. Wow.

I kind of wish I had seen that. But I gotta finish the last thing he says, because he describes the demise of this uh, this, this giant in the seven League boots uh quote, thousands of them are annually blown into the Black Sea and here, once in contact with water, in an instant, lose the fantastic grace belonging

to their dry, unsubstantial texture. They are like, oh, it's it is like a witch like melting in the water because the power, it's so good, the wind, which that I've been captivated by that ever since I read it. These things are are wind witches. Um. But so okay, this is describing something in like the what they're calling the Russian Step, probably the area around the Black Sea, the Black Sea basin, or probably around Ukraine. So how

does this type of plant end up in the United States. Well, beginning in the later decades of the nineteenth century, reports of a similar plant. I can't be sure they're talking about exactly the same species, but it seems likely to me, uh, they're They're at least definitely talking about the same type of plants, some kind of tumble weed. UM. Reports of a similar type of plants start pouring in from places in the Great Plains of North America, places like South Dakota,

UM and Uh. It's hard to know exactly when they showed up, but a commonly reported claim put forward in a source I'm going to mention in a minute here is that they arrived in the United States around the year eighteen seventy or sometime in the early eighteen seventies, possibly in shipments of flax seed contaminated with these Russian setle seeds UM. A commonly given date is eighteen seventy three. It is interesting to read reports from the early decades

of their proliferation on the continent. By the eighteen nineties, invasive Russian thistle had become such a problem that the U S Department of Agriculture Botany Division issued a farmer's bulletin on the subject, authored by someone named L. H. Dewey. The l H stands for Lister Hoaxe Dewey, So you can actually look up a PDF of this yourself online. It's called the Russian Thistle and other Troublesome Weeds in the Wheat region of Minnesota and North and South Dakota.

This document is actually more interesting and fund to read than you might expect for a farmer's bulletin. Uh So, so there's a number of tidbits I want to discuss from it, but first of all, I just want to read directly from it, as it is discussing the difficulty that farmers in the planes were facing due to the proliferation of tumbleweeds, probably from from Russian thistle. So Dewey writes, some of its special characteristics render this thistle much more

troublesome than other weeds. Again, it's not actually a thistle. It is armed with spines quite as sharp and much stronger than those of common thistles. Because of these, it is difficult to drive horses through a field where the plants are abundant. In some sections, the farmers find it necessary to bind leathers about the horses legs while at work. Horses running in the pasture are often injured by having the skin on their legs badly lacerated. The spines breaking

off under the skin cause festering sores. These sores are caused by the irritation, however, not by any poisonous property, as is frequently supposed. Hunters find difficulty in getting their dogs to work well for prairie chickens and the stubble, and the dogs are sometimes injured by the sharp spines. Thrashers find it almost impossible to get gloves thick enough to keep the spines out of their fingers, yet thin enough to work with. Oh, and then he talks about

how these tumble it's can be a fire hazard. Of course, so he says, the Russian thistle is the worst rolling tumbleweed on the prairie, and in time of prairie fires, is easily blown across a firebreak of any width, carrying fire to stacks and buildings. Yeah, so, yeah, this is the thing. Not only can they potentially be a fire hazard once they arrive at sort of a termination point, you know, when they're stuck against the fence or a house, but they can be on fire and be in motion.

And uh and probably one of the more outrageous examples of this UM was making the rounds on the internet I think back in uh and it took place at a hundred and fifty acre um prescribed burn at the Rocky Mountain Arsenal near Denver, Colorado. And if you haven't seen this footage, look it up. I think it was

making the rounds, especially on like BuzzFeed news and stuff. UM. But what you see is you see firefighters out there, you know, engaging in this um, you know, intentional burn of the of landscape there, and a dust devil kicks up, so you know, like a small vortex. And what does it do. It starts pulling tumbleweeds up into it. And uh and and this is I've seen footage of this occurring um with tumbleweeds elsewhere, except in this case the tumbleweeds are also on fire, so it is essentially a

dust devil of flaming tumbleweeds. Yeah, it's like it looks like a tornado made out of tumbleweeds that are on fire. Right, it seems I mean it just sounds like a shark Nado sort of a situation. But no, it exists. I mean, it would seems like the main characteristics that are the problem here that tumbleweeds are so they're brittle, you know, fuel their their woods, so they're they're highly flammable, and they're very low density, so they can easily be moved around.

And of course when there is fire, that creates drafts of air that that suck and blow things in different directions on its own. Uh So, yeah, tumbleweeds plus fire just seems like a nightmare to try to con troll. Now, naturally, one thing you would do to prevent fire from spreading, say in a prairie region, as you would have what are known as fire breaks. You would have you know, like ditches or areas of cleared land where there's no fuel.

You know. So it's just like, if there is a fire, it's going to be stopped here because there's no fuel for it to spread across. But if you have tumbleweeds, first of all, they're they're they're likely to gather in fire breaks anyway, because that's the kind of you know, they will fall, they will settle their seeds in cleared land and grow grow there, so they can grow in fire breaks. When they're tumbling, they'll probably get stuck in

fire breaks and pile up there. And uh and even if there's nothing in the fire break, if there's tumble if there are tumbleweeds burning on one side, they can easily leap over the break and then just spread it to the other side. You know, when I first encountered this, I also was thinking, Okay, maybe this is just a rare thing though, a flaming tumbleweed. I mean, just because it's on BuzzFeed News doesn't mean it's an accurate representation

of reality. Um. But then I was looking around at some various folkloric references to tumble weeds, most of which I'm gonna say for part two. But there is this one bit from a folkloreist by the name of Thomas Edward Cheney who lived nineteen o one through who specialized in Mormon folklore and folklore of the bad Lands, and he wrote this in nineteen fifty nine in Scandinavian Immigrants Stories quote, A story glows like a tumbleweed on fire.

As it passes on it may die after a brief and flashy existence, or it may be retained in the mind of a jokester until he dies and leaves his legacy to members of his family. They in turn recall sporadically the stories which particularly resemble their experiences. Many such stories die without the folkloreist or anyone else getting them into the written language. Now, that's just a good quote

about just sort of the nature of storytelling. And I just kind of like what he's actually trying to relate there. But I also love that, like that that here is the flaming tumbleweed as a as a metaphor to explain that, and clearly like one that's not so novel as to be foreign. I guess two people of of of this part of the country. Like, he doesn't have to stop and say, let me tell you a story about a tumbleweed that once caught on fire, and I'm gonna use

that to make my point. No, like the tumbleweed on fire seems to be just, you know, more or less off the shelf, even if it feels a little novel to many of us. But I like that metaphor. Actually it has both, uh in terms of oral storytelling, it has both its strengthened its fragility there because a tumblewheat on fire will burn up pretty quickly, and so it's

it's very fleeting, it's very ephemeral. But on the other hand, it's you know, it spreads super easily, so if it if it reaches another fuel source there it goes Yeah, absolutely, thank thank But anyway, so in this document, this Department of Agriculture document from the eighteen nineties, L. H. Dewey goes on to talk about some of the same kind

of problems we've already discussed in the modern age. You know that they will pile up against buildings, that they will pile up against fences, that they will will choke fields, that they will even if you kind of mulch them down. Uh. That they may do some good in in nourishing the land, but just that they're hard to deal with. When they're in their bulky form, they just get stuck in all

kinds of stuff and and cause these huge problems. Uh. There was another very interesting note I came across in this. There was more just to kind of uh something mentioned in passing in this document, but I thought it was sociologically interesting. So in discussing where Russian thistle comes from. Dewey says, all the evidence points to the idea that it was imported in contaminated shipments of flax seeds that were received in in the States around eighteen seventy three

or in the early eighteen seventies. And then he goes on to say, quote, there is evidently no foundation whatever for the theory which is too often related as a fact that it was first son in South Dakota by immigrants, either for forage or to inflict an injury on an enemy. So at least as early as the eighteen nineties, people were spreading a completely baseless rumor that this invasive plant was due to immigrants who had sowed the weed on purpose,

possibly even with the intent to cause harm. Very much uh mo on the Simpsons immigrants, I knew it was them. But then later Dewey is talking about how quickly it He's trying to document how quickly the Russian thistle spread. Uh He says, quote, in many localities where a few plants were first seen four or five years ago, every spot of land where the sod has been broken is now occupied on every badger burrow and over fed spot in the prairie, on every roadside, railroad, embankment, firebreak, and

neglected garden. On every field of early plowed land or stubble may be seen a patch of thistles. Again, not thistles. These are the tumble weeds. Uh. The seeds are not here and there as with eastern weeds, but they are everywhere. The few plants introduced four or five years ago have seeded the land for miles in every direction. Um. And then the last thing in the document is a section I actually found somewhat hilarious where he issues recommendations that

are they're like pure just like vilification propaganda. I mean, not like obviously you know, these tumbleweeds can be a huge problem, and I'm not saying like I would just ignore them, but he like recommends that every school house in America should have a Russian thistle in the school house so that the pupils may become familiar with it quote and teach them to kill it wherever they find it,

as they would kill a rattlesnake. Oh my goodness, I really feel for for many of us that, you know, they didn't grow up in tumble weed country or haven't been visiting tumbleweed country during the times that they're on the move, like this is just kind of a uh, this this great adversary that's been there the whole time and we and I feel like I didn't really recognize it until just now. Well I think it is technically

now in all forty eight contiguous US states, so it's everywhere. Yeah, Like I mean, it is in Georgia, the state where we, uh we record this, But I do not recall ever having seen it or you know, identified it as such while I was here. I certainly have not had that experience of you know, the herds of of them moving across the highways, though I can only imagine how Georgia drivers would would would respond to that. We don't take

kindly to stuff invading our highways. Now, I just wanted to mention a few other interesting facts that came across in another article. I was trying to look for a a more recent article about the spread of the different tumbleweed species, especially ruscent Russian thistle and related species in

the US. So there was one I read from eighteen in the UC Boulder, Colorado Arts and Sciences magazine by you See Boulder professor of evolutionary biology and ecology named Jeff Mitton and Mitton covers some of the same ground we've already talked about that, for example, that tumbleweed is

a is a structure. It is a type of strategy for reproduction that is employed by many plants, but that in the American context, most of the time when people see a tumble weed or talk about a tumble weed, they're usually talking about this Russian thistle species Salsula tregas

or Callie tregas and uh. He says interestingly that genomic analysis in California has revealed that the tregas, the main species, was introduced to the US multiple times, at least twice from different places, so there were multiple introduction events, and he emphasizes against something that that has come out from

multiple sources. We've looked at that tumbleweeds became especially common as they took hold in otherwise barren areas or in quote over graized sites, so abandoned farmlands or or overused ranch lands could be especially good places for UH for for these things to take root. They do better in cleared land where they can scatter freely, where their seeds

don't have to compete with native grasses and shrubs. So it seems like one way to have a place resist colonization by the by the tumbleweeds is just to have

plenty of natural native vegetation covering the land. One last thing I want to mention that that Mitten brings up in this article is that, uh, you know, sometimes discussion of of aggressively spreading non native species of plants can I don't know, it caused people to think of a plant as being wholly without use or merit in any you know, it can provide no nourishment to anything at all.

And while tumbleweeds can certainly be a big problem for for humans and other life forms, Mitten points out that some animals can eat the sprouts of of these tumbleweed plants and and can get nourishment for them, especially when they're young and green, but he says that herbivores do tend to avoid them once they have reached their their thorny brittle adult state. Though he points out one interesting historical fact about their use as nutrition in in American history.

He says that tumbleweeds quote were one of the last plants growing during the dust Bowl nineteen thirty to nineteen thirty six, when many farmers and ranchers were unable to keep anything growing to feed cows and horses. Russian thistle hay is credited with saving the beef cattle industry when other sources of hay disappeared. So this is a species of plant that that plays rough, but when when nobody else can hack it, it is still there and you know,

in its young form it it can be eaten. Who may not be the best food source in the world, but but the bovines can ingest. Anyway, I think that'll have to do it for part one of our series on the Wind, which the tumbleweed. But we've got a lot more interesting stuff to talk about in part two. Oh yeah, we've got some some crazy tumbleweed variants that may interest you. We've got we've got we've got a

few Mongolian riddles we're gonna share. Uh So, there should be a lot of a lot of interesting territory to cover, but we're gonna go ahead and let this particular tumbleweed episode snap off at the roots and begin tumbling its way to listeners out there. Obviously, even yeah, with creativity

in the metaphoric sense. Right Um, now, I'm sure we have a number of listeners out there who have a lot more experience direct experience with tumbleweeds, and yes, we would love for you to share your experiences with us, uh, encountering tumbleweeds, rolling across the highways and into your house and so forth. Um let us know you know how to get in touch with us, and we'll share that

information here in just a second. But hey, in the meantime, if you would like to listen to additional episodes of Stuff to Blow Your Mind, you can find them in the Stuff to Blow your Mind podcasts. Feed Core episodes published on Tuesdays and Thursdays. On Monday's we do listener mail. On Wednesdays we do an artifact or a monster fact episode.

On Fridays, we do Weird House Cinema. That's our time to set aside most serious matters and just to focus in on a strange film and discuss a strange film. Um oh, I should also point out that I was just looking to to revamp some of our you know, place holders, social media presences, and our Instagram account has been locked up for over a year. Nobody knows how to get into it. It's a ghost house. So we

have a new Instagram. If you're into Instagram and you want to follow us, you can follow us at st b y e M Podcast. That's our handle there. But I should also point out that we also have a separate Instagram for Weird House Cinema, and that one is just Weird House Cinema. That's the that's the Instagram handle, and uh, that one I've actually updated, so it has like a still from every episode of Weird House Cinema

that we've done thus far. So that's a fun way if you just want to follow Weird House Cinema stuff. And I'll probably be updating that because because every now and then, when I'm watching a movie for a Weird House, I'll have to like take a picture of something on the on the on the TV screen, um, and this might be a place where I would share that. So so yeah, I'm liable to actually use that account for things beyond just the mentioning of new episodes. This is

this is phone camera photo of a TV screen. Yeah, yeah, that's has more heart. Yeah. I think the first one the post I did on that Instagram account was it was just a picture I took off the screen during Hands of Steel where it has the text at the end that pops up and says it was a day in our near future the era of the cyboid had begun Arizona movie, so it ties in to what we're talking about here today. Not unrelated to tumbleweeds. There you go,

drifting along with the tumbling cyborg. Okay, anyway, huge things. As always to our excellent audio producer Seth Nicholas Johnson. If you would like to get in touch with us with feedback on this episode or any other, to suggest topic for the future, or just to say hi, you can email us at contact at stuff to Blow your Mind dot com. Stuff to Blow Your Mind is production

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