In 2014, two Colorado cities declared states of emergency due to tumbleweeds. In January 2020, a large number of tumbleweeds appeared on Interstate SR240, more than 30 kilometers west of West Richland, Washington. These hundreds of tumbleweeds not only blocked the road ahead, but also buried a large truck under a 4.5-meter-high pile of weeds. …


It looked really miserable. Image source: Twitter

Every fall and winter, a large number of grass balls grow out of thin air on the plains of the Midwestern United States. Not only do they roll and "run and jump", they also gather in groups. Although it looks a bit funny and cute from a distance, it is not that easy to get along with. Most people in the United States hate this "troublemaker".

Tumbleweed is actually a general name for a type of plant that can roll with the wind after drying. Most of the tumbleweeds that are raging in the Midwest of the United States and serve as their iconic "landscapes" are a plant called Kalitragus, which belongs to the genus Salsolaris of the Amaranthaceae family and is native to Russia, Austria, Germany, Qinghai, Tibet and other places in China.


The theme of the next superhero movie may be called "Jackass vs. Tumbleweed." Image source: YouTube

Tumbleweed didn't look like this at first. It used to be a green, very watery plant, and could even bloom small white flowers. Many animals, including black-tailed deer, pronghorn antelope, prairie dogs and birds, feed on the succulent young shoots of spiny sapodilla.

Moreover, during the dust storms in some areas in the 1930s, it was used as feed to keep cattle from starving as no other feed was available.

But in autumn, when everything begins to wither and wither, it naturally cannot escape death. The branches begin to dry up, and the parts above the ground are disconnected from the roots underground. As long as the strong wind blows, the tumbleweed, which is not bound by roots and has a wandering nature, begins its journey.


White and delicate, how old are you now? ! Image source: wiki

Speaking of which, the United States is not within the range of the origin of Saphopus spp., so why is it still flooding? actually,The spiny sapodilla is an invasive species in the United States.

In the 1870s, when the United States imported flaxseed from Russia, it accidentally brought Echinacea into the country. Tumbleweed, who had just arrived, behaved very reservedly at first, without any thoughts or signs of wanting to "become the king", so the local people didn't care about it that much.

But the good times did not last long, and after only 20 or 30 years, the thorn sapodilla began to overflow. Today, the plant is found in all states except Alaska and Florida.


Local people who enjoy themselves in hardship. Pictures come from the Internet

The reason lies in the strong reproductive ability and environmental adaptability of Acanthus striata. A spiny sapodilla can carry about 200,000 seeds. When they roll, the violent tumbling will help it shake out the seeds.

When the time is right, these seeds scattered on the ground will grow into new spiny sapodillas, and the cycle repeats. Moreover, because they require less water and have good tolerance to salinity, their growth environment is rarely restricted and they can grow freely along beaches, grasslands and the Gobi Desert.


Sow the seeds like this. Image source: tenor

In addition, due to the relatively flat terrain of the United States, the plain area accounts for half of the country's land area, and the plain area has good ventilation conditions. It provides a favorable terrain for the movement of tumbleweeds: not only are there no obstacles, but the wind is relatively strong.

The tumbleweed uses the force of the wind like a bouncing wheel, rolling and jumping at the same time.It can even move more than ten kilometers a day, constantly expanding its population range.


It really looks like two conscious creatures (Image source: YouTube

This tough, prickly plant can clog irrigation ditches and spread pests. The tangled dry branches of tumbleweed are particularly flammable and can pose a threat to human life if they catch fire when they roll across a fire line or pile up against structures such as houses.


Tumbleweed's Way of Survival: Savage Invasion. Image source: YouTube

Overflowing tumbleweeds often invade highways and streets.Residents in the American Midwest woke up to find their doors blocked, their houses buried, or their cars buried.Encountering invading tumbleweeds on the highway may block the driver's view and cause a traffic accident.


Come and experience a little bit of the shock of tumbleweed! Image source: tenor


Shocking +11111 Picture source: YouTube

Many measures have been taken against spiny sapodilla and other tumbleweed species, such as pesticides, cutting down seedlings or pulling them out before the seeds have a chance to develop, and mass burning.

But these methods are often expensive and time-consuming. The USDA is also testing specific natural enemy insects and viruses imported from Russia, the plant's main homeland. In 2014, the U.S. Agricultural Research Service announced the discovery of two promising fungal pathogens, Suromycessalsolae and Colletotrichumsalsolae, in the hope that they could infect and kill tumbleweeds.


Image source: tenor

There are two reasons why tumbleweed has not overrun our country. First, it is a native species and part of the ecosystem. There are corresponding natural enemies that can curb its overgrowth. In addition, our country is mostly mountainous and hilly, and the terrain is undulating, which is not conducive to tumbleweeds rolling to spread their seeds.


Salsa hirsutum. Image source: PlantsofWorldOnline

As for the saying that "we ate all the tumbleweeds so they didn't overrun", this is actually a rumor! The Amaranth family, where tumbleweed comes from, is rich in food ingredients, and the most well-known ones are amaranth and spinach.

It is true that the young leaves of Echinacea are edible, but what people eat so much is actually Salsolaris, which looks similar to it and belongs to the genus Salsolaris of the Amaranthaceae family. So oftenThis leads some people to mistakenly think that what they are eating is bushi and that they are saving the world (bushi).

References

[1]https://www.usatoday.com/story/news/nation/2020/01/01/tumbleweeds-bury-cars-drivers-washington-state/2792122001/

[2]https://agresearchmag.ars.usda.gov/2014/sep/weed

[3]https://www.treehugger.com/everything-you-ever-wanted-know-about-tumbleweeds-4864166

[4]https://bie.ala.org.au/species/https://biodiversity.org.au/afd/taxa/f32becff-d994-4673-803b-1d58cce32130

Planning and production

Source丨Bring science home (id: steamforkids)

Author｜A Xian Editor of "Everything" magazine

Editor丨Yang Yaping