The science of giant mushrooms

[Pandabear]

In some exotic fantasy settings, a common environment is forests made out of giant mushrooms, ranging from your basic garden gnome variety to towering fungi with glowing spores. Now that made me wonder a bit for a setting I have in mind, and in particular about the laws of physics and biology of oversized mushrooms. I might need the aid of a mycologist here, but I'm interested to know the following:

1) Provided the right amount of nutrition, sunlight, and other factors, how large could a mushroom potentially become? What would the upper limit be of the size and mass of a mushroom?

2) What would the material be like of a giant mushroom? Would it be squishy? Would it resemble some sort of wood? Could one make a bow out of it?

3) What would the structure of the mushroom itself be like? Would it have year rings? Could you make dwellings out of it and make doors without the the nails of the hinges falling out?

4) How fast would they grow? Would a race of fungus dwelling people live one story higher every year?

Just some technicalities I was wondering about. Hope someone could clarify things. Thanks!

[Eldan]

Well.

I wouldn't know about mushrooms, since they don't really need to be all that big for what they do (spread spores), but fungi can be come really, really big. As in, largest organisms on Earth.

From Wikipedia:
A giant fungus of the species Armillaria solidipes (honey mushrooms) in the Malheur National Forest in Oregon was found to span 8.9 km2 (2,200 acres),[4] which would make it the largest organism by area. Whether or not this is an actual individual organism, however, is disputed: some tests have indicated that they have the same genetic makeup,[5] but unless its mycelia are fully connected, it is a clonal colony of numerous smaller individuals. Another clonal colony that rivals the Armillaria and the Populus colonies in size is a strand of the giant marine plant, Posidonia oceanica, discovered in the Mediterranean near the Balearic Islands. It covers a band roughly 8 km (4.3 miles) in length.[6]

Anyway.

While basic mushrooms are indeed pretty squishy, I'd assume that there would be some sort of woodlike material to keep them up if they are rivalling trees in height. There are some fungi which already get pretty hard, so that should work. In general, they include chitin in their cell walls instead of cellulose as plants do, but they would have to have an equivalent of lignin as well.
At least in trees, the limiting factor of height is water transport: capillary effect and the suction effect of evaporating water limit them to a height of a little short of 110m. Fungi would have to adapt pretty much most of what plants already have for water transport to get anywhere near that size.

Mushrooms in general don't differentiate very much. The material inside it would, unless they evolve into some interesting new directions, be more or less uniform.

Mushrooms, generally, grow amazingly fast. Some grow over night. However, at that size... not much faster than trees, I'd assume.


Another thing to note: you can't really have a community made up solely of fungi. They are decomposers, not producers like plants are. So, they need organic material from somewhere else to break down. (Some are radiotrophic, but that's a rare exception). You could take a point from Lichen, though, and make your fungi symbiotic with algae, which would also make a nice explanation for luminescence.

[nedz]

Mushrooms are just the fruiting bodies of fungi. The actual organism lives mainly underground (or inside trees etc). These networks are capable of living for many years, the fruit though are short lived: their only purpose is to spread spores.

[Yora]

When it comes to fungi, you can go pretty outragous while still keeping close to what's physically possible given the right environmental factors that lead to species evolving that way. And when you're willing to let a bit more fantasy into and assume that there are some mechanisms at work that don't exist in real world species, you can go even further while still keeoing things mostly plausible.

Of all the bizare concepts of modern fantasy and sci-fi, giant mushroom forests are among the most plausible.

[Eldan]

Really?

Now, speaking from just a very general ecological perspective, what reason is there for Mushrooms to grow really tall?

Additionally, just where do they get their nutrients from?

[Zaq]

If I remember my old biology classes, fungi are generally (or is it always?) decomposers, so they need some kind of dead matter to suck nutrients out of. They don't photosynthesize, so they need some kind of organic material to eat (dead and decaying things are pretty much where it's at). That's the biggest problem with a good old "giant mushroom forest" situation . . . you have to feed them something, and that something has to come from somewhere.

Interestingly, if you look at it from a certain angle, those Githyanki cities on the Astral Plane that are built on the bodies of dead gods could theoretically work. I have no problems imagining a mushroom forest decomposing a dead god. You could even get some interesting philosophy out of that (the druids who take a hard-sell circle of life approach vs. the clerics who believe that the dead gods still deserve respect, for instance).

Anyway, as has been stated, the mushroom parts of the fungi are kind of like flowers . . . as a rule, they're just reproductive structures, and they don't have much reason to be there for terribly long (or to grow terribly large). You'll have to invent some kind of handwavey reason why the mushrooms don't just pop up, scatter some spores around, and wither (while the primary part of the fungus, which is usually buried happily underground, stays strong and happy and generally not as much fun as a giant mushroom).

It's been a long time since I read Underdark, but wasn't there stated to be some kind of Phazon-style radiation down there that influenced how things grow? That could provide both the energy source and the reason for the unnatural behavior in a single stroke.

[Eldan]

There are a few radiotrophic fungi that actually seem to use radiation as their energy source, but apart from that, yes, being composers is universal for fungi.

The problem with the dead gods, of course, is that they aren't living material but mostly stone.

[nedz]

The problem with the dead gods, of course, is that they aren't living material but mostly stone.

Aahh - its not science, but it is fantasy: Giant Mushrooms eat stone :smallcool:
No not specifically dead god stone, but any old stuff. Well, specific rock types possibly, but whatever.

[Eldan]

Of course, of course.

But the OP asked about real Fungi. I'm sure that with magic, you can find explanations for pretty much all of the ecological problems of giant fungi.

[nedz]

Yes I know, but he did start out by saying :smallamused:

In some exotic fantasy settings, a common environment is forests made out of giant mushrooms, ...

[Dsurion]

Well, regarding the problem with mushroom forests needing a source of food, there is this:
http://en.wikipedia.org/wiki/Ophiocordyceps_unilateralis

It's a mushroom that basically infects an ant and turns it into its zombie slave :smalleek:

Perhaps not exactly what you were looking for, but it seemed relevant.

[nedz]

Cool - can we give it levels of Cleric for Necromancer ?:smallbiggrin:

[Eldan]

Seems to me Telepath would fit better. Probably going into Trallherd.

[Volthawk]

Interestingly, if you look at it from a certain angle, those Githyanki cities on the Astral Plane that are built on the bodies of dead gods could theoretically work. I have no problems imagining a mushroom forest decomposing a dead god. You could even get some interesting philosophy out of that (the druids who take a hard-sell circle of life approach vs. the clerics who believe that the dead gods still deserve respect, for instance).


Hmm, that would be kinda interesting. I'm thinking decomposing the bodies of dead gods releases divine essence (or energy, or whatever makes them all godly and stuff), so the fungi get enhanced by the divine essence, making them large and perhaps with a few other supernatural boosts.



It's been a long time since I read Underdark, but wasn't there stated to be some kind of Phazon-style radiation down there that influenced how things grow? That could provide both the energy source and the reason for the unnatural behavior in a single stroke.

Huh, that could work too, I guess. I guess fungi enhanced by that would be more extraordinary and physical than supernatural/magical, unlike the divine boost.


Well, regarding the problem with mushroom forests needing a source of food, there is this:
http://en.wikipedia.org/wiki/Ophiocordyceps_unilateralis

It's a mushroom that basically infects an ant and turns it into its zombie slave :smalleek:

Perhaps not exactly what you were looking for, but it seemed relevant.

Yeah, those things are cool. Now, if you gave it a supernatural boost, say making them psionic, they are now psionic fungi that can take over creatures and make them slaves, and mindrape the victims into liking it. :smalleek:

[Loki_42]

There are a few radiotrophic fungi that actually seem to use radiation as their energy source, but apart from that, yes, being composers is universal for fungi.

Really? I'd like to here some of their work.:smalltongue:

[Eldan]

Sure.

Here. (http://www.youtube.com/results?search_query=wailing+fungus&aq=f)Disclaimer: I only know the band because they showed up on Futurama once, where they were real fungi. No idea what their music is like.
Have fun.

[Admiral Squish]

I REALLY like the idea of a decomposing ecosystem bourne on the back of a dead god. The world rots beneath your feet. Fungi cover the ground in a low layer of small mushrooms and other growths. Giant mushroom forests. Scavengers that tunnel through decaying flesh. Capillary caves, massive arterial caverns, and awe-inspiring organ hollows. Perhaps even an evil cult dedicated to exploring the arteries to find the heart of the dead god and revive him. Death is LITERALLY everywhere.

[Benejeseret]

Food Source:

That could make an entire campaign plot onto itself - what could be the source of such a massive fugal growth?

Dead god? Or perhaps they feed on a immobilized Tarrasque, sapping its strength but it regenerates endlessly. Fungi farmers and the industry growing from their harvest (making bows, using in house building etc) cutting them down is related to earthquakes and eventually the release of big T.

[klemdakherzbag]

As for buildings made of giant mushrooms look no further than the Telvanni Dunmer on Vvardenfell (The Elder Scrolls - Morrowind ) but I think they just said "its magic" as to their growth...

[Eldan]

Telvanni strongholds were indeed magic (you can even grow your own), but Vvardenfell seemed to have naturally occurding giant fungi as well.

[ericgrau]

1) Provided the right amount of nutrition, sunlight, and other factors, how large could a mushroom potentially become? What would the upper limit be of the size and mass of a mushroom?

2) What would the material be like of a giant mushroom? Would it be squishy? Would it resemble some sort of wood? Could one make a bow out of it?

3) What would the structure of the mushroom itself be like? Would it have year rings? Could you make dwellings out of it and make doors without the the nails of the hinges falling out?

4) How fast would they grow? Would a race of fungus dwelling people live one story higher every year?

Just some technicalities I was wondering about. Hope someone could clarify things. Thanks!

1. Trees have a special mechanism for transporting water. I imagine the height limit on mushrooms would be limited to the same as the height limit on plants, maybe 15 feet.

2&3. Fungi have little structure, even less than plants, hence the problem in #1. Even the cells don't have borders between eachother; their insides actually spill into eachother. A more rigid structure would require cellulose cell walls, which I don't believe they have. But thick sections should hold their shape well like blocks of styrafoam, even have some rigidity and bounciness due to the thickness. Probably no bows. Construction techniques would be more like carving than anything. Connecting multiple chunks together would more likely involve glue than nails, or some other attachment over a large area. They'd have to use some kind of preservative to keep the mushroom from rotting. I'm not familiar with these but there should be some plant or another or alchemy to provide it.

4. Mushrooms typically pop up full size overnight. There's a larger fungus below a bed of mushrooms that releases these as fruiting bodies. I suppose a civilization might preserve and carve these as they pop up, thinning away the ones in undesirable locations and using them for food.

To feed them there are likely to be some non-mushroom plants somewhere. For example an underground cavern below a forest could have the mushrooms. Or a cave full of bat guano. Or underneath much taller trees, even sharing space with their roots. Or downhill from some other form of life.

[Skaven]

Could have them 'feed on magic' and have them growing on a land with a lot of latent druidic/natural magic.

[CockroachTeaParty]

Along the 'dead god as food' line of thought, there's other potential sources for a giant mushroom forest.

There's an entire layer of the Nine Hells that is now the corpse of a former Archdevil. Likewise, certain mythologies have origin stories of the planet as being the body of a massive being, such as Eberron or Norse mythology describing the world as the corpse of a particularly huge giant.

[Eldan]

2&3. Fungi have little structure, even less than plants, hence the problem in #1. Even the cells don't have borders between eachother; their insides actually spill into eachother. A more rigid structure would require cellulose cell walls, which I don't believe they have. But thick sections should hold their shape well like blocks of styrafoam, even have some rigidity and bounciness due to the thickness. Probably no bows. Construction techniques would be more like carving than anything. Connecting multiple chunks together would more likely involve glue than nails, or some other attachment over a large area. They'd have to use some kind of preservative to keep the mushroom from rotting. I'm not familiar with these but there should be some plant or another or alchemy to provide it.

They may not have cellulose cell walls, but they have chitin cell walls. The problem would be the lack of Lignin.


4. Growth for most non-trees are usually measured in months not years. I suppose they'd get full grown fairly quickly provided that they had plenty of decaying organic matter to eat. That's how mushrooms get food by the way; they don't need light and some don't like it either. Thus there are likely to be some non-mushroom plants somewhere. For example an underground cavern below a forest could have the mushrooms. Or a cave full of bat guano. Or underneath much taller trees, even sharing space with their roots. Or downhill from some other form of life.

While it's true that Mushrooms grow faster than trees, if they were actually as big and rigid as trees, I see no reason why they should actually be much faster. Especially since they had to adapt special mechanisms for water transports first.

[ericgrau]

Thought I'd check the wiki for the growth rate and mushrooms pop up very fast and edited my post accordingly. IIRC if you're lucky you can watch it happen right before your eyes. That's because there's a bigger fungal mass underground that is slowly growing and spreading through its food. The actual mushrooms people live in might be popping up all over the place, fully formed underground, then popping out and umbrella-ing within a few minutes. Maybe a few rounds if you want to have some fun with it. Each round of combat you roll the random mushroom percentile. While unlikely it could raise a group of monsters or PCs to a higher elevation over the span of a couple rounds.

[nedz]

Sounds like mushrooms would be great for LARP weapons, but little else:smallbiggrin:
Frisbees maybe ?

[faceroll]

Another thing to note: you can't really have a community made up solely of fungi. They are decomposers, not producers like plants are. So, they need organic material from somewhere else to break down. (Some are radiotrophic, but that's a rare exception). You could take a point from Lichen, though, and make your fungi symbiotic with algae, which would also make a nice explanation for luminescence.

Or you could just rule that fantasy fungi can do whatever the heck you want, because it's fantasy. Have them eat rocks (like a delver, no one whinges about delver biology), or be magitropes, living off the powerful energies that run through the land. Or heck, maybe they can even photosynthesize! Photosynthetic mushrooms is hardly a stretch when you've got dragons and ghosts. IRL, there's a shrimp that fires sonic lances hotter than the sun to stun its prey. Adding chloroplasts to fungus doesn't seem that exotic, in comparison.


Really?

Now, speaking from just a very general ecological perspective, what reason is there for Mushrooms to grow really tall?

Competition for sunlight and/or dispersing efficacy. Get the spores up high in the air column, better dispersal. Or creation of microhabitat for its spores.

[ericgrau]

Mushrooms don't need nor like light. Spore dispersal or simply being a really big variety makes sense.

Feeding on old latent druidic or other magic sure would fit the mushroom's style of consuming leftover decaying material. Or the ancient underground decaying god/titan/etc. is cool too. Or there are plenty of other ways to have decaying plant matter or poop in the area, or drain into the area from above/uphill.

Any other way to feed like photosynthesis kind of makes me cringe. Feeding on decay is their thing. It would be like underground man eating plants except they don't need anything else and they don't need light so they're not green and they move and think... and well at some point it's no longer a plant. Likewise for mushrooms.

[faceroll]

Getting big is a good way to exclude competitors from an area. I forgot about all the weird chemo-autotroph archaea out there. The lithoautotroph (literally stone eating) geogemma barossii lives in hydrothermal vents and uses iron in place of oxygen as an electron acceptor, and hydrogen as an electron donor. In reducing iron, it creates magnetite. Microbes that makes magnets. Pretty cool.

[Eldan]

Or you could just rule that fantasy fungi can do whatever the heck you want, because it's fantasy. Have them eat rocks (like a delver, no one whinges about delver biology), or be magitropes, living off the powerful energies that run through the land. Or heck, maybe they can even photosynthesize! Photosynthetic mushrooms is hardly a stretch when you've got dragons and ghosts. IRL, there's a shrimp that fires sonic lances hotter than the sun to stun its prey. Adding chloroplasts to fungus doesn't seem that exotic, in comparison.

Said before: sure. Nothing wrong with that.

However, the OP asked about real fungi, and I gave answers relating to real fungi. Changing their fundamental aspect would, more or less, not make the mfungi anymore. I suggested lichen or radiotropes. Magitropes are another possibility.

[drakir_nosslin]

Bombard the forest with dead organic material from space every ten years or so. Solves the food issue, and the 'shrooms need to be tall to get as much food as possible (openings on the top 'eat' the spacefood).

Then you've got a nice little plot hook as well. It might even be hard space food that destroys the forest completely and then the characters get to adventure in the area as the forest regrows, changing areas completely over just a few weeks.

[Erik von Nein]

You could have huge fungal forests by first having the fungus in your setting be tree parasites. So, they'd have to intermingle with trees, but it'd be much more reasonable to have mushrooms all over the place if they're parasitizing the tree's nutrients. Hell, have them be beneficial in some way, like root fungus. Have them be aggressive in releasing toxins or some such, just to throw in an extra challenge for the party. Get too close to a fungus-infected tree? Get a face full of toxin spines.

[faceroll]

Mushroom forests could also be transient. They don't necessarily have to be permanent forests. They could grow on 400 year cycles, sprouting up, burning down, being replaced by something else, or colonizing new areas.


Bombard the forest with dead organic material from space every ten years or so. Solves the food issue, and the 'shrooms need to be tall to get as much food as possible (openings on the top 'eat' the spacefood).

Then you've got a nice little plot hook as well. It might even be hard space food that destroys the forest completely and then the characters get to adventure in the area as the forest regrows, changing areas completely over just a few weeks.

You could even go further and have fungus live on negative energy. They grow on bones and old battlefields, the remains of fallen undead armies. Every century or millenia or so, an atropal scion drifts past the world, trailing behind it an assortment of undead, like a charnel meteor. The world passes through this macabre tail, showered with undeath. Most of those undead are destroyed in their fall or the land revolts at their unnatural passing and swallows them up. In time, their remains become food for the great underground mushroom forests.

Though I like a dark, unseelie moon, haunted with fey, the pale, twilight world covered in inky dark seas and mushroom forests. It's from there the giant mushroom spores fall, taking root in places rich with fey magic.

[Volthawk]

Hmm, I'm thinking some fungi can absorb magic from the surrounding area, and perhaps other energies as well (like Incarnum), which gives them magical abilities depending on what kind of energy they are charged with.



You could even go further and have fungus live on negative energy. They grow on bones and old battlefields, the remains of fallen undead armies. Every century or millenia or so, an atropal scion drifts past the world, trailing behind it an assortment of undead, like a charnel meteor. The world passes through this macabre tail, showered with undeath. Most of those undead are destroyed in their fall or the land revolts at their unnatural passing and swallows them up. In time, their remains become food for the great underground mushroom forests.


I was thinking about negative energy fungi, and I had a thought. What if negative-energy charged fungi raise zombies with their spores as well as infesting inside them? Would mean areas infested with this type of fungus would be quite dangerous, as being killed there means you get undeadified, meaning resurrection is harder. And perhaps not all things killed by the undead made by the fungi are raised, allowing other types of fungi to decompose the body.

[faceroll]

I was thinking about negative energy fungi, and I had a thought. What if negative-energy charged fungi raise zombies with their spores as well as infesting inside them? Would mean areas infested with this type of fungus would be quite dangerous, as being killed there means you get undeadified, meaning resurrection is harder. And perhaps not all things killed by the undead made by the fungi are raised, allowing other types of fungi to decompose the body.

But not only that, the zombie hosts would serve as both a dispersal mechanism and a way to get new food/hosts.

zomg, this is going in my campaign. :smallsmile:

[Volthawk]

But not only that, the zombie hosts would serve as both a dispersal mechanism and a way to get new food/hosts.

zomg, this is going in my campaign. :smallsmile:

Yeah. Also, these fungi/spores could be gathered by less moral characters, and used as a weapon. I mean, get some into a field hospital of an enemy force, for example, and then the whole place goes into zombie apocalypse mode. Or perhaps negative energy fungi could drain life for sustenance (like how a wight gets health from Energy Drain).

[Zaydos]

http://en.wikipedia.org/wiki/Prototaxites

Wikipedia article about a giant fungus (doesn't seem to have been updated in the last 4 months). It had a fruiting body that grew over 20-ft tall (my paleobotany teacher said almost 10 meters) and looking at the fossils could almost be mistaken for the primary and secondary xylem in trees (in laymen's terms wood).

So tree size fungus is possible.

[faceroll]

Yeah. Also, these fungi/spores could be gathered by less moral characters, and used as a weapon. I mean, get some into a field hospital of an enemy force, for example, and then the whole place goes into zombie apocalypse mode. Or perhaps negative energy fungi could drain life for sustenance (like how a wight gets health from Energy Drain).

I love plague campaigns. This is definitely going to get used.

[ericgrau]

http://en.wikipedia.org/wiki/Prototaxites

Wikipedia article about a giant fungus (doesn't seem to have been updated in the last 4 months). It had a fruiting body that grew over 20-ft tall (my paleobotany teacher said almost 10 meters) and looking at the fossils could almost be mistaken for the primary and secondary xylem in trees (in laymen's terms wood).

So tree size fungus is possible.

It still wasn't vascular (trees are) meaning the theoretical height limit is 34 feet for water to reach the upper areas and those fungi in particular grew to 25 feet. Interesting, I didn't think most non-vascular things would get above 15 feet.

[nedz]

Yellow Musk Zombies FF 190.
Not quite fungi I know, but it would be easy to re-fluff.

[Volthawk]

I love plague campaigns. This is definitely going to get used.

Heh. Of course, there's also the RL fungus from earlier, with the enhancement I mentioned:




Well, regarding the problem with mushroom forests needing a source of food, there is this:
http://en.wikipedia.org/wiki/Ophiocordyceps_unilateralis

It's a mushroom that basically infects an ant and turns it into its zombie slave :smalleek:

Perhaps not exactly what you were looking for, but it seemed relevant.

Yeah, those things are cool. Now, if you gave it a supernatural boost, say making them psionic, they are now psionic fungi that can take over creatures and make them slaves, and mindrape the victims into liking it. :smalleek:

So psionic fungi like this would perhaps have intelligence, and since they would take over living bodies, and through charming, mind-reading, etc. could infiltrate society, before spreading its spores, like the RL one does in ant colonies, just in towns/cities etc. And it could even disguise the reproductive stalk under a hood or hat...

[Eldan]

http://en.wikipedia.org/wiki/Prototaxites

Wikipedia article about a giant fungus (doesn't seem to have been updated in the last 4 months). It had a fruiting body that grew over 20-ft tall (my paleobotany teacher said almost 10 meters) and looking at the fossils could almost be mistaken for the primary and secondary xylem in trees (in laymen's terms wood).

So tree size fungus is possible.

Heh. Remember when I mentioned that giant mushrooms could be lichen? Apparently, this could have been one. I love being right :smallbiggrin:

Suddenly, it also makes sense for them growing tall: they need sunlight now.

[Mikeavelli]

Bombard the forest with dead organic material from space every ten years or so. Solves the food issue, and the 'shrooms need to be tall to get as much food as possible (openings on the top 'eat' the spacefood).

Then you've got a nice little plot hook as well. It might even be hard space food that destroys the forest completely and then the characters get to adventure in the area as the forest regrows, changing areas completely over just a few weeks.



This!

Moderately plausible evolutionary thing: An irregular food source appears every few years that demolishes the Fungi forest.

The destroyed Fungi release spores that cover the food source and grow rapidly.

The giant part comes in when it turns out the dominant species of fungus is able to store vast amounts of nutrients inside itself, and slowly self-cannibalize until the next cycle of foodstuffs show up.

Smaller species of fungus run out of food and die off before the food source comes back, so they've been selecting for the largest possible fungus. After centuries of this happening, you now have tree-sized fungi.

Other, smaller fungi have survived by being able to acquire secondary food sources, like curious adventurers. This consists of any of the other poison/zombie/etc. fungi that have been proposed elsewhere in the thread.

[Eldan]

Ooh, I know!

There's a ring of organic material around the planet. Space-adapted aberrations, maybe, or asteroids with plants on them (screw the atmosphere necessary for plant life, canonically, D&D space is filled with Phlogiston anyway).

Every so often, one of these crashes on the planet.

[Benejeseret]

Beholders ARE the fungi spores.

Bam

[Eldan]

Alternatively: an elephant-graveyard like scenario. A kind of large creature comes there irregularly to die, possibly in herds.
Or something like certain kind of migratory fish: they come to reproduce, die, leave their offspring behind. On that biomass, a fungal forest grows up, which also provides the living space for the offspring. The offspring grow up, the forest dies down, they offspring migrate away.
Repeat X years later.

[Pandabear]

Very interesting discussion so far, and a lot for me to think about. Thanks guys! Also, nice that people are getting inspired by the idea :smallsmile:

As an environmental DM, I like to put emphasis on making the place the players play in interesting and dynamic. Having the players see giant mushrooms sway in the wind while exotic species flitter about has this certain ambience that puts the group in the right mood right away. I like to keep the magic to a minimum here, but having a forest of these things for which how it works is not readily explainable is mystery enough.

For some of the issues presented, I have thought of one solution: a 'breathing' mushroom cap. The cap contracts and expands, pushing air down to pump water up, and when it breathes out it expels a hot pocket of steam in all directions. Once in a while these pockets are used to expell large and heavy spores across the surface below, where people have to avoid them in order not to get crushed, and the height of the mushroom is required to give them proper momentum to get as far away as possible in order to not compete with food with the parent mushroom. At the surface, there are burrowing large insects with a short lifespan, providing food.

[claricorp]

I have explained stuff like this to my players before. In an underground area there were massive fungi with cup shaped tops. Occasionally a crack would form in the ceiling and let in water from an underground lake creating mineral and nutrient rich rain for the fungi to survive off of.

The ceiling cracking and reforming was part of the plot.

[Eldan]

For some of the issues presented, I have thought of one solution: a 'breathing' mushroom cap. The cap contracts and expands, pushing air down to pump water up, and when it breathes out it expels a hot pocket of steam in all directions.

Interesting solution, and I like it. Requires a few adaptions, though:

1) Vascular structures (i.e. "tubes"), as plants have them, to transport the water. As in plants, you could include valves to stop the water from flowing back. Most likely rigid.

2) The bigger problem: muscle-like structures for the pumping. This skyrockets the mushroom's energy requirements.

[Volthawk]

Hmm, a thought. Perhaps one individual fungus does all the dispersal (with the breathing cap and whatnot), and others supply it with the spores to spread and energy to do it with? Then only a few fungi out of the forest would need to use so much energy, and the others don't have to take spore dispersal into consideration.

[Pandabear]

That requirement might be lessened considerably by introducing some kind of waterpump action. We take ridges that go from the center to the rim of the cap, and that rim has a sort of sphincter that contracts and relaxes. Once it contracts, the ridges pull up, heightening the cap, increasing the volume and thus decreasing the pressure, when it relaxes the pressure is increased and air is pushed down by the weight of the roof of the cap. Somewhat the idea of a lever mechanic, but different.

Having the idea of having a sort of queen fungus is an idea, but I'd say the other fungi would supply genetic material underground when spores are expelled. This leaves the water requirement however..

[Randel]

Some ideas:

1. The main body of the fungus exists underground and sucks life out of living creatures. Every once in a while the fungus grows huge mushrooms that spread their spores around. The spores are basically harmless and the mushrooms themselves could be full of magic or just make really good food. Its only the parts underground that are dangerous to living things.

The humans on the surface just see the mushroom stalks and these only appear every few decades or so... and when it happens its a time for celebration! The spores get all over but they are harmless (might make good alchemical or magical componets) and the stalks themselves look cool until you chop them down and eat them (the kingdom harvests the mushroom stalks before they decompose, preserves them, and sells them as a delicacy). There might be some problems if the "nutrient gathering'" parts start growing in compost heaps or whatever but then its nothing some fire and stuff can't fix (On the First day of Fungimas day we sat beneith the caps, seeing the glittering spores as the drifted cross the sky. On the fifth day of Fungimass we harvested the caps, had ourselves a feast that we never would forget. On the tenth day of Fungimas we cleaned up the land, burning all of the moldy things to keep our kingdom clean!)

So the humans just see the fungal spores and think of them all as a blessing or at the very worst a reason to have a holiday where they burn moldy things.

Underground however the fungus permeates the rock and makes it really hard for dwarves, kobolds, or gnomes to make their caverns. The fungus sucks life out of anyone it touches and has the tendancy to cover any particularly magical or valuable ores it comes in contact with. The Dwarves know of huge chunks of earth that simply can't be safely mined because the fungus infests it... and every time they hit one of those spots the fungus grows out into their existing caverns.

But... it turns our that in the very center of that massive mass of fungus is a terassque or other powerful monster that simply can't be killed. The fungus had grown around it and leeches its energy to keep it from ever awakening, plus it kills anyone who might dig close enough to free the monster.

Some greedy dwarves might want to kill the fungus in order to get at all the valuable ore its keeping out of reach or someone else might try to destroy it to free the monster its sealing up.


2. A necrotic fungus releases spores that animate dead things. The resulting zombies go out to kill people snd bring their bodies back to the fungus. It continues to animate the dead and send them out to collect more until the mushroom caps start to wilt... at which point the zombies all return to the fungus grounds (along with whatever organic material they can carry) so they can collapse and feed the fungus.

The infested area is often littered with the bones or the dead and all the valuables they might have carried on them. Hardy adventureres or scavengers might go into the area to steal whatever magic items or valuables are on the zombies, or maybe look for valuable bits of ivory or animal bones.

It could also be that the skeletons littering the fungus field are the first to animate, the skeletons go to kill things and harvest them but they cannot be reanimated. The zombies resulting from the initial kills can be reanimated as longs as they are placed beneath the fungus caps and exposed to the spores.

The whole zombie apocolypse thing only happens once every few years but always starts with the mushroom caps growing. The caps act both as as releasing the spores that animate zombies and as a 'transmitter' that controls them. Zombies who travel beyond the range of the mushrooms will still try to gather bodies for the fungus but they can't find their way back. They'll just stand there holding a body or maybe wander around aimlessly trying to find their way back.

So when the fungus apocolypse starts then one can either kill all the zombies and skeletons, or head for teh mushroom stalks and destroy them to disable the zombies. The fungus area is still full of poison, half-destroyed skeletons blindly groping from beneith the ground, lots of disease and filthy flies covering the dead bodies, and the spores and tendrils of the fungus (which aren't something you want to get too exposed to).

[flabort]

Heres my (mostly, somewhat) original ideas:

The fungi grow in metal rich environments, absorbing but not using the metals. What they really eat/use is not important, yet.
When the fungi fruits and produces mushrooms, it pushes the metals out with them, creating thick skeletal structures allowing the mushrooms to gain height, and spread their spores out further.
When the mushrooms then shrivel and "die", they leave behind the metal frame.
The fungi itself grows/migrates away, leaving a veritable forest of metal spear like protrusions.
Other life forms move into the hollow, but extremely durable homes left behind by the mushrooms, and this becomes a vibrant ecosystem. There are entrances, but only at the bottom.
The fungi migrates back after a couple years, having completed it's migratory loop. The life forms ahead of it start to die, for the reason below.
It grows up through the metal pipes, feeding on the lifeforms now trapped within, as it has blocked off the entrances.
It keeps moving forward, life forms X dieing off ahead of it, then trapping/eating life forms Y. The lack of the latter causes the former, by the way, as the former relies on the latter.
The fungi shoots out more mushrooms, and since it's grown into the pipes it left last time it was here, it causes pipes to grow out from the pipes.
It migrates away again, the fungi still in the pipes dying, leaving even more room for a vibrant ecosystem to show up. In fact, the lifeforms chase the fungi for the homes it leaves, while the fungi chases the lifeforms for food, in an unending loop of death and decay, chase and devour.
Repeat, repeat, repeat. This will leave huge tangles of jointed branching pipes, resembling a Darker steampunk factory, but in fact being a "Mushroom forest".


Definitely not quite what the OP is after, and not very much what's been discussed already, but it's pretty neat.
I'd imagine dwarves would follow and glean Cycles of this fungus to obtain free metals from it. However, they wouldn't take it all, or that could end up upsetting the balance of the ecosystem.

[OracleofWuffing]

Warning: Non-scientific, artist fridge-logic ahead, did not do the research.

Mkay, let's say you got a forest with huge trees with which to start. One day, there's an epic magic fight, maybe that monk stepped on the wizard's grass one too many times, maybe that Artificier wanted to carve out that tree to make a house and that Druid didn't like the idea too much. Anyway, the biggest freakin' tree in the forest gets knocked down, burned up, zombified, struck by lightning, liquefied, whatever suits your boat for how the combat went down.

Now you've got a forest with a big ol' dead tree as fungus-fodder. Now that the biggest tree in the forest isn't exactly using its root system, surrounding trees are gonna notice the comparative flood of unused nutriments and go, "Hey that's mighty tasty I'm gonna eat this up and grow big, om nom nom nom nom." The resulting growth in surrounding trees creates shade for mushroom fodder, I think that's enough, environmentally, to get started on the fungus.

Okay, so what makes the fungi so big? One option, I didn't mention it before but there's a waterfall by the forest. The surrounding water is coming down from the falls into the forest, so it's still got a bit of force going to it. Hence, the mushrooms don't pull water in actively, it just flows into them. The force of water also encourages further growth, effectively stretching it out. Yeah, I wasn't kidding when I put that disclaimer at the top. :smallannoyed:

Additionally, the fungus develops a taste for living flesh and starts spreading and feeding off the surfaces of surrounding tree trunks. Maybe critters are eating the bark off trees, so there's a little bit of aid getting to the more vulnerable parts of the tree. The big thing to draw from this, though, is that the fungus really doesn't need to build a complicated system of tubes for moving water when there's one already existing in the forest trees.

So, yeah, now the fungus is wrecking down the forest. Close dead trees die, fort saves but you still take ongoing parasitic damage. Thing is, dead trees means you lose the shade that previously fostered the fungus. So, we got a cycle of fungus kills trees, fungus dies, trees regrow, fungus regrows, repeat. Eventually, natural selection and/or divine/arcane influence kicks in. The mushroom feeding off of the trees figures out it needs to make super-huge caps (using the tree branches as support) in order to provide itself continuous shade. Eventually, what you see as a giant mushroom is really a colony of the stuff that's basically grown around and "absorbed" a tree, and that huge reproductive structure is basically unused by the "body" except it's using its own corpse to protect itself from sunlight.

After a long enough time passes, the mushroom eats all that's left of the supporting tree and basically collapses under its own weight. Then self-cannabalization starts.

:smallyuk: Geez, mushrooms are disgusting.

[Pandabear]

Keep in mind though, to try to have something that could theoretically work without using magic is just my idea. If you guys think of something based on magic or something that would make most mycologists weep, but you can get the right effect for your players, go for it! :)

[ericgrau]

As an environmental DM, I like to put emphasis on making the place the players play in interesting and dynamic. Having the players see giant mushrooms sway in the wind while exotic species flitter about has this certain ambience that puts the group in the right mood right away.

Ambience is aweseem IMO



For some of the issues presented, I have thought of one solution: a 'breathing' mushroom cap. The cap contracts and expands, pushing air down to pump water up, and when it breathes out it expels a hot pocket of steam in all directions. Once in a while these pockets are used to expell large and heavy spores across the surface below, where people have to avoid them in order not to get crushed, and the height of the mushroom is required to give them proper momentum to get as far away as possible in order to not compete with food with the parent mushroom. At the surface, there are burrowing large insects with a short lifespan, providing food.

Pumping water is only necessary for taller mushrooms. One poster posted an ancient 25 foot tall mushroom with no such mechanism. The theoretical limit is 34 feet, but the practical limit is probably less than that. I'm not fond of given fungi much structure like a vascular system, but a simple pumping mechanism could work for taller mushrooms. One such way similar to other slow moving plants would be to fill hollow chambers with a gas produced by some reaction from their food. Air is about 1/1000th the density of solids, so it wouldn't take much food. As they balloon this pushes on and causes another section to flex and thus expand or contract to suck in water or expel air. Valves to prevent pushing back water during contraction or to avoid sucking in air during action expansion could be simple flaps of tissue that only open in one direction like heart valves (http://en.wikipedia.org/wiki/Mitral_valve). Once high enough the water could be held in the chamber and soak to where it's needed over time. Each cycle might take minutes or maybe hours. It is energy intensive so I don't know if it would actually be worth it.


I have explained stuff like this to my players before. In an underground area there were massive fungi with cup shaped tops. Occasionally a crack would form in the ceiling and let in water from an underground lake creating mineral and nutrient rich rain for the fungi to survive off of.

The ceiling cracking and reforming was part of the plot.
Things are a lot easier to explain with underground mushrooms. You don't need any such crack (though I admit plot > science). Water from above will still seep down. If there are plants above, water runoff from decaying matter like leaf litter will provide plenty of food.

[Asheram]

Well, regarding the problem with mushroom forests needing a source of food, there is this:
http://en.wikipedia.org/wiki/Ophiocordyceps_unilateralis

It's a mushroom that basically infects an ant and turns it into its zombie slave :smalleek:

Perhaps not exactly what you were looking for, but it seemed relevant.

That is some of the scariest **** i've learnt about nature in a long while...

[flabort]

That is some of the scariest **** i've learnt about nature in a long while...

There was another thread that took that MUCH further. They had the mushrooms infecting all humanoids, in a modern setting.
Imagine people with the sole though "Must get higher", winding up on the roofs of towers, and their heads exploding into spores. On second thought, you don't need to know.

[Benejeseret]

Helping the size issues:

Perhaps the 'breathing' mechanism can be more passive, similar to the huge termite/ant colony mounds which uses solar convection to draw air in and through a hollow system of tubes/tunnels.

The water balance is harder to get. The simplest options are likely the best and we've had a few good ones to pick from. The easiest is to just assume a very wet climate.

Perhaps the spores are changing the entire environment...literally seeding the clouds and increasing precipitation. Anyone caught in the rain end up with a rot disease. Leads to a zombie-apocolypse of yellow musk zombies.


EDIT:

That is some of the scariest **** i've learnt about nature in a long while...
A number of viral and parasitic infections influence behaviour patters (rabies aquaphobia, toxoplasmosis daring, etc). Then with the fact that up to 15% of our own 'human' DNA is viral in origin we start to wonder how much of our behaviour is actually human, or what human is...

[Set]

[Edit: Doh, just noticed that someone else already posted an idea almost identical to this upthread. Great minds thinking alike? Psychic plaigerism? Whatever, I'll take it. :)]

If dead gods are a bit extreme, the underdark might be littered with the corpses of critters whose bodies don't decay the same way. Perhaps, in the right situations of moisture and warmth, a troll's body doesn't stop regenerating (at a much slower rate), even after it dies. The remains keep repairing lost tissue, but the creature never revives from whatever made it 'brain-dead,' and ecosystems can thrive on these never-ending meat-buffets.

Instead of trolls, perhaps larger creatures, stunted lesser cousins to the dread tarrasque, or regenerative elder versions of purple worms, once crawled through the earth, tunneling caverns and mindlessly seeking flesh. Slain in ages past, their colossal corpses continue to generate fresh tissue, which fungi and vermin endlessly predate in vast underdark 'forests.' The actual bodies of these creatures lie at the centers of these forests, buried under massive colonies of fruiting fungi and monstrous vermin of all sorts, while some of their tissue has long since become separate from the core body (such as limbs pulled free), and yet still contains unnatural remnants of life, healing inexorably from the constant damage done by vermin and fungus.

Thousands of yards from the central bodies of these rare corpses, mushroom 'trees' still sprout, pushing up from the bodies of the fungus below the ground, nourished by the distant body, thus accounting for mushrooms that seem to be growing too far from the long-buried body to be gaining sustenance from it (as they are being fed by underground fungal networks).

Perhaps there's even story potential here, and the razing of a mushroom forest and uprooting of the fungal growth (and accompanying scavenger vermin) might result in the 'dead' monster being able to regenerate more successfully than when it's constantly attempting to keep up with being devoured from all ends, and stirring back to life...

"Yeah, we burned down the fungus forest that was the source of those monstrous centipedes that have been raiding our underdark village!"

"And now the dormant elder tarrasque-worm-thing they were feeding off of is awake. Good job!"

.

And there's always the mysterious underdark radiation thing, as mentioned upthread. Any fungus that has leaned to thrive on that energy source is going to do well for itself. Alternately, the fungus could thrive on the dead bodies of creatures that themselves subsist off of 'underdark radiation,' although that puts them at a different stage in the 'food chain' and makes the mushroom forests dependent upon these other critters remaining in the area...

[Qwertystop]

Something awesome:
Get creatures which look like normal humans infected by a fungus, like the ant one, but they're actually sentient fungus that grow appearing to be humans.

Alternately, make a "race" of sentient fungi that is actually one enormous fungus that spreads through the world, and the members of the "race" are actually semi-ambulatory portions. Maybe they need to "root" once a day, the same way humans need to sleep, but they're not resting and gathering nutrients, they're reconnecting to The One and updating to the hivemind. Of course, nobody knows this. Might work best if the campaign setting has these races as a recent addition to the "known" sentient races, to explain/handwave why the secret hasn't been found out yet.

EDIT: You know, i'm just going to go and put that on the Request a Homebrew thread now, just because it's awesome.

[gorfnab]

I'm surprised no one has mentioned Nausicaä of the Valley of the Wind, considering the fungi infested toxic forests and the spores they release into the air. This could easily be adapted into a D&D world or campaign setting.

[Eldan]

On the regenerating creature issue:

Trolls were mentioned how about this:
If a Troll dies by drowning or suffocation instead of acid or fire, it's brain dies, but the body doesn't stop growing. This means that you'd find ever-regenerating troll corpses along rivers and lakes, where it's also nicely moist for fungi.

[Pandabear]

Parasite spores messing up humanoids: wicked!

Giant mushrooms feeding on regenerating Trolls: one could conceivably think of an alignment plane where dead Trolls go to when they die, and being fed for eternity to giant mushrooms is their due for improper life..

[Eldan]

I'm not even sure: do trolls have gods?

[Pandabear]

Not sure if they do, but when you have Thor as a deity in a setting, I'd expect the Trolls to worship Ymir, from which body the world was made.
Without the Edda's available, there's probably some book or supplement somewhere that gives a conclusive answer :)

[randomhero00]

IIRC oxygen concentration (used to be higher around the dinosaur era) are especially needed for larger plant life and insect life.

And yes, some mushrooms are nearly as hard as wood. I could certainly see a society based around it. Only thing they'd need is a magic way for them to get nutrients (and possibly more oxygen if the atmosphere is like ours). Otherwise, they'd need a reason for animals to come in and die a lot there. Or well, its gross but poop a lot there (like bats in a cave). Sometimes guano gets so high its over 10 feet and all sorts of things take refuge. Since we're thinking of fantasy, the bat-like creature could nest in these giant mushrooms rather than caves.

[GolemsVoice]

One could also make the fungi have an aura that automatically drains all living beings of energy, and does it very, very slowy. So the people in the mushroom forests always look pal, sick and unhealthy, and one might ask why they don't leave. They don't want to. But who cares about them, they are an odd folk anyway, and if you're clever, traveller, do not spend a night among the people of the mushrooms.

This could be nice for an Innsmouth-type of campaign. The fungi feeds on his people, will at the same time covering them in spores that makes them complacent and forces them to stay here. They would form an outsider community, shunned and feared by normal folk, who have all kind of superstitions about them. And if your heroes stay to long, well, they just might never leave....

EDIT: Think of the powerful image: A dark, gloomy forest of fungi that are unnaturally tall, and look... evil, somehow. Twisted, dark. As you step beneath the mighty caps, the twilight surrounds you, but the pale, hollow faces of the people never turn to look at you. Only after repeated asking do you get a room at what passes for a tavern here, and the innkeeper acts mechanically, never looking at you directly, moving slow and cumbersome, fumbling with the keys. You guess he's probably 35, but he sure looks much older...

[Benejeseret]

Don't worry Set, great minds think alike :smallbiggrin:

I always like a twist so here's one I had after reading your troll bit.

What if the fungi is the high regeneration thing, and it grants the property to things it infects? In that setting Trolls and the like would actually be infected villagers whose disease has overtaken them. The theme could be to go out of your way to pick regeneration monsters to populate the fungal forest. Big T would still be a good end game though in that case

[subject42]

Really?

Now, speaking from just a very general ecological perspective, what reason is there for Mushrooms to grow really tall?

Additionally, just where do they get their nutrients from?

Based on this here link (http://news.discovery.com/earth/tallest-fungus-prototaxites.html), the reason for mushrooms to get big is to spread their spores further.

These could get 25' tall and had smooth, straight fruiting bodies, kind of like logs.

[Set]

What if the fungi is the high regeneration thing, and it grants the property to things it infects? In that setting Trolls and the like would actually be infected villagers whose disease has overtaken them.

Ooh, that's a neat twist!

1e trolls had those wiggly head things that looked very much like mushroom growths, come to think of it...

[Pandabear]

Well, my basic idea was to go for exotic, think Myst, and not really for horror.. Although I must say, this train of thought is interesting in itself for that.

Infecting people with spores might be beneficial at first. People get smarter, more socially aware, and they become the center of attention because everybody starts to like them and they come up with the better idea's.. Until a point where the person vanishes. They feel the call of the forest, go there, and take root, never to be seen again in their humanoid form.

[kiergon]

You can have harder than wood fungi material, the mycelium of certain fungi species can grow really hard, harder than concrete and Termites dislike its taste, so they wont go near it
The Mycelium is the root system (which is the main body) of a fungus.

http://www.time.com/time/magazine/article/0,9171,1957474,00.html

You could have in theory a species of fungus that grows in an underground cavern, to grow very large, and they could be harder than most woods.
as for their diet? They could be Radiotrophic and feed of a natural nuclear reactor, we have had those in the past here on earth.

http://en.wikipedia.org/wiki/Oklo

So if you can stretch science a little bit, I think it could have been very possible for a fungi to evolve to form large forests in an underground cavern, and they would feed on radiation from a natural nuclear reactor.
For extra points you could make it glow in the dark due to Cherenkov Radiation.
http://en.wikipedia.org/wiki/Cherenkov_radiation
And if fungi couldn´t evolve to be as tall as say a pine, then they could be symbiotic with a plant, they provide the nutrients bye the radiation-melanine process and the plant provides the support structure.


Damn that would look cool, a giant fungi forest in an underground cavern with either fungi that glow in the dark in an eerie blue color or the floor itself glows in the dark. The fungi themselves are as hard as concrete, and you have a race of aberrations that fold light around them living there.

[Pandabear]

Well, for my idea it doesn't have to be above ground, so in a large cave would also be possible.. I am considering fungal dryads though, so perhaps I can do something with that too..

That piece about harder than concrete fungi is awesome, albeit mainly for real life purposes..