Episode 03: Horny Yaks & Fungal Horror- Cordyceps

Jan 18

A close up of one variety of cordyceps in bloom on the body of a grub that is under the soil.

For centuries, humans have been growing along side our botanical brethren. Our histories have mixed and mingled to bring us modern medical marvels, fated folk lore, and everything in between. Of course, In order to understand the plant, we have to start with it’s roots…..I’m Em Grebner-Gaddis, and this is rooted.

This week we are taking a closer look at Cordyceps- a species of fungi in the ascomycete genus, and the antagonist of the hit series “The Last of Us”.

Cordyceps are primarily endoparasitoids, meaning that they grow INSIDE of a host (usually a specific bug) until eventually their fruiting bodies burst out to spread their spores.

The word Cordycep Comes from greek word kordýlē meaning club, and cephali, meaning head…so you can remember them by thinking of them as the WORST party hats of all time.

Cordyceps can mostly be found growing in humid and temperate places like Nepal, China, Japan, Bhutan, Korea, Vietnam, and Thailand, but we even have a few species here in high altitude regions of north america. While they all look pretty different and have a variety of hosts, the way they operate is pretty similar across the board.

Cordyceps infect their host with spores, which spread through the hosts body as the fungus grows. As the mycelium develops, it replaces the host’s tissue, surrounding it’s muscles and vital organs, eventually seizing control of them. As the fungus reaches maturity, it starts forcing the host (an ant, caterpillar, or beetle in most cases) to move to a spot where it will be better able to spread it’s spores. See, fruiting comes at a cost- as soon as the fungus reaches maturity, it begins to die.

Once the Cordyceps has gotten it’s host to the right location, it waits for it’s next victim. For this part we will focus on ants, as this is where the behavoirs have been most observed. In Ants, Cordyceps move the host down from the trees (where they live) and on to a common path- usually one the ants use to go get food. This is because the ant’s dont like leaving the nest- with the threat of being a snack looming overhead and risk or getting crushed around every corner, you probably wouldn’t either…. And when they do leave- it has to be for good reason- like gathering food. They tend to stick to the same known paths, so it’s pretty easy to find a spot with plenty of new hosts.

The reason that the Cordyceps go through the trouble of using jedi-mind (more like muscle) tricks is that they They NEED the cooler temps and higer humidity of the forest floor. They would never reach maturity in the trees. So, they force their hosts to climb down and wait.

Once the host gets to a prime location. The Cordyceps waste little time reaching maturity. The fruiting body will eventually split the ant’s head open, then a long finger-like stalk will rise from the ant’s neck. Soon, tiny little bumps will form on the end of the stalk- those are the fruits, and the Cordyceps are ready to spread, and the cycle repeats itself.

I know what youre thinking- something this horrific MUST be out of science fiction…and in a lot of ways you’re right. But to get there, we have to start with the history of Cordyceps in the cultures they come from.

In Ancient Tibet, it is said that the power of Cordyceps was discovered after a farmer noticed his yaks acting strangely. They were full of energy and seemed to be in much better spirits than normal. The famer wondered what could possibly be causing the sudden change in mood, and that’s when they noticed the Cordyceps the yaks had been eating.

This variety of cortoceps was found to be Ophiocordyceps sinensis. It targets ghost moth caterpillars that live in the tibetan plateau. It’s said to be an aphrodesiac, as well as being used to improve kidney function, circulation, respiratory function, and to help with curing things like the cold and flu. \

Because of it’s role as a miracle cure, it has been touted for centuries, with wild Cordyceps fetching a pretty penny at local markets. As word has spread about this fantastic fungi, prices increased. Its estimated that up to 30% of tibets GDP comes from these little guys trough both trade AND tourism. As you can imagine, a market that big has lead to a TON of competition and over harvesting.

In fact, this wild fungus has led to some pretty violent turf wars and in fighting about who should get to harvest wild Cordyceps, where, and if there should be limits on how many any one group can harvest.

Because of this, many commercial mytocology labs have begun growing these alien- like mushrooms themselves. While some reports claim the lab grown stuff isnt as potent, the technology and technique has come a long way from early days. Now scientists are able to cultivate more consistent strains, without needing bugs as hosts.

William Padilla-Brown from Mycosymbiotics has a whole detailed video on how they cultivate Cordyceps on his youtube channel, but I’ll do my best to cover it quickly here:

To start, he creates the base: this is what the mycellium grows in…so basically he is recreating the nutrients and environment one might expect to find in a bug’s body.He uses coconut water, tapioca starch, magnesium sulfate, crushed multi vitamins, soy peptone or nutritional yeast, Kelp Powder, and gypsum to create his base, and mixes that in on some brown rice. The brown rice has lots of sugars of the mycellium to eat, and gives it plenty of area to latch on to while it grows. From there, he keeps the jars in a controlled environment- making sure to keep temps and humidity JUST RIGHT for them. If these two things fall out of wack, the Cordyceps might die before flowering, or worse, other fungi might start taking over- contaminating the Cordyceps and ruining the harvest.

But if everything is done right, the Cordyceps will start sending up their creepy little fruiting bodies up, and before you know it, you’ve got usable Cordyceps- ready to be shipped off for study, or for use in a variety of teas, tinctures, and pills.

While Cordyceps can be used for good, there is no denying that they are straight up sinister. Their terrifying nature lends itself particularly well to fiction, and has influenced a TON of pop culture recently.

Most notable is probably The Last Of Us, were a new Cordyceps species begins spreading to humans as a result of climate change. In this franchise, the Cordyceps spread through spores, but the fruiting bodies are more thread like in nature, and don’t split through the hosts head, but rather sprout out of their mouths. It is only after the host has spread the spores thoroughly that the fungus begins to spread outside of the body through the eyes and forehead eventually leaving nothing more than a skeleton.

Other notable projects influenced by Cordyceps are the 2018 film Annihliation, the 2019 game bug tales, and the 2014 book The Girl with all the Gifts.

While Cordyceps have certainly played a large role in the horror genre, they are also a vital character in moden medicine. Today, Cordyceps are used in medicines given to organ transplant recipients due to their immunosuppressant properties. The species Cordyceps subsessilis lives in the grub larvae of the scarab beetle, and contains cyclosporin, which helps to suppress the white blood cells that would recognize the new organ as an outsider, and helps to keep them from kicking it to the curb. While that is SUPER helpful, this can also be really really hard on the kidneys, which is interesting given that its cousin Cordyceps sinensis is being studied to help improve kidney health.

And there you have it- a little more info about the most famous fungal anti-hero. I hope you enjoyed this little deep dive into a very creepy zombie fungus and all that it brings to the world through both medicine and pop culture.

That’s all for this week If you liked this show, please consider subscribing, and leaving us a review on spotify, apple podcasts, or anywhere else you listen. You can follow us on facebook, instagram and tiktok at Rooted.pod. We’re on youtube at rooted.podcast, and check out our website rootedpod.com for transcripts, updates, and so much more. Thanks for being here, and until next time, be kind to yourselves, be kind to the earth, and just like a plant- drink your water.

Sources

https://alohamedicinals.com/a-history-of-cordyceps-everything-you-need-to-know-about-one-of-the-most-common-medicinal-mushrooms/

https://ohiomushroomsociety.wordpress.com/2022/07/05/cordyceps-the-myth-and-the-mushroom/

https://storiesfromthemuseumfloor.wordpress.com/2017/10/27/cordyceps-the-zombie-fungus/

https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD008353.pub2/full

https://www.science.gov/topicpages/m/medicinal+mushroom+cordyceps

https://www.theatlantic.com/science/archive/2018/10/tibetan-caterpillar-fungus-trouble/573607/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3924981/

https://instagram.com/mycosymbiote?igshid=YmMyMTA2M2Y=

https://mycosymbiotics.com/blogs/news/stalking-the-wild-cordyceps-militaris-except-from-book

https://www.youtube.com/watch?v=ei9J04C1MPU

https://www.imdb.com/title/tt2798920/