|
 Some of these posts are very old and might contain outdated information. You may wish to search for newer posts instead.
|
 Nomad
Mad Robot
Registered: 04/30/02
Posts: 422
Last seen: 16 years, 9 months
|
 The Visibility of Poison 
#1310782 - 02/15/03 10:16 PM (21 years, 7 months ago) |
|
|
Feel free to kick me out if I'm in the wrong forum. I just thought that, if anyone can solve this riddle for me, it would have to be the hunters.
Poisonous plants and animals usually have some sort of visible clue, things like red colour, or an unusual smell. Basically, conditional triggers for animals, which serve as reminder that this thing is dangerous. Would you say this holds for mushrooms, too? There are bound to be exceptions to every rule, but would you say that, by and large, poisonous mushrooms look more "weird" than non-poisonous mushrooms?
This is related to a thread in S&P&S, where I tried to make some sort of argument that mushrooms are unlikely to produce psilocybin as a poison, since members of the psilocybe species seem to have no visible clues.
Thanks for your help. From me, and science, too. 
|
ToxicMan
Bite me, it's fun!
Registered: 06/28/02
Posts: 6,731
Loc: Aurora, Colorado
Last seen: 5 hours, 36 minutes
|
Re: The Visibility of Poison [Re: Nomad]
#1310883 - 02/16/03 02:55 AM (21 years, 7 months ago) |
|
|
I would say that one of the main reasons the deadliest mushrooms are dangerous is their lack of noticeable signs indicating danger.
The mushroom species which causes the most fatalities is Amanita phalloides. It is a large, attractive looking mushroom, and accounts from people who have eaten it indicate that it is very good tasting.
False Morels (Gyromitra) cause the second most fatalities in the US. Again, these tend to be large, attractive mushrooms which taste good. Compounding the problem with these mushrooms is the fact that the poison shows no symptoms until one has reached dangerous levels. The result is that there are a lot of people who eat these over and over again without harm until the day when they get an extra large batch or maybe some of them just happen to have more toxin in them than usual.
On the other hand, one would expect that the mushrooms which cause the most harm would be exactly those which don't show the sort of signs which might deter one from eating them. And there are certainly a number of poisonous mushrooms which are pretty much never eaten for various reasons.
I also hunt wild, green plants of various types to eat. Using my mushroom hunting experience as a guide, I made sure I learned the potentially deadly plants before I picked anything. Here (in Colorado) there has never been a death due to mushroom poisoning. I don't know the statistics for deaths due to poisoning by green plants, but I know there have been deaths. I would even rate the nastiest of the deadly plants as far more dangerous that mushrooms. The deadly mushrooms here will mostly take days to weeks to kill their victim, allowing time to seek medical attention. Some of the deadly plants can kill in minutes to hours.
Larkspur (Delphinium), Monkshood (Aconitum), Poison Hemlock (Conium maculatum), and Water Hemlock (Circuta douglasii) are all extremely dangerous plants which can cause fatalities. The last one (Water Hemlock) is reputed to be the most toxic plant in North America. One mouthful can be lethal. It resembles carrots or parsnips (it's in the same family). It kills through respiratory and cardiac depression.
The question of why various mushrooms or plants produce toxins is an interesting one. Since many mushroom spores will not survive the trip through a digestive system it seems reasonable to guess that the poisons are there to prevent them from being eaten. The main animals which eat mushrooms are insects and rodents. So we should look to the effects on those animals when speculating on the reason for their production.
--------------------
Happy mushrooming!
|
Nomad
Mad Robot
Registered: 04/30/02
Posts: 422
Last seen: 16 years, 9 months
|
Re: The Visibility of Poison [Re: ToxicMan]
#1310952 - 02/16/03 03:55 AM (21 years, 7 months ago) |
|
|
Thanks! That helped me a lot.
Since many mushroom spores will not survive the trip through a digestive system
Sure about that? I thought that spores are hard-shelled enough to survive digestion (similar to plant seeds). Also, Amanita phalloides looks incredibly dangerous to me, not attractive at all. Indeed, all large mushrooms look somehow dangerous to me (me not being an expert at all), so maybe largeness could be considered a sign of poison (to an animal)?
|
Nomad
Mad Robot
Registered: 04/30/02
Posts: 422
Last seen: 16 years, 9 months
|
Re: The Visibility of Poison [Re: Nomad]
#1310959 - 02/16/03 04:02 AM (21 years, 7 months ago) |
|
|
Regarding spores & digestion, I think a young specimen of amanita muscaria has a higher toxicity than an old one, so maybe the posion is produced to avoid that the early mushroom is being eaten before he can produce spores? Also, it seems to me that a mushroom which grows in symbiosis with trees would not profit by being eaten, even if the spores survive digestion,
Edited by Nomad (02/16/03 04:02 AM)
|
ToxicMan
Bite me, it's fun!
Registered: 06/28/02
Posts: 6,731
Loc: Aurora, Colorado
Last seen: 5 hours, 36 minutes
|
Re: The Visibility of Poison [Re: Nomad]
#1311054 - 02/16/03 05:12 AM (21 years, 7 months ago) |
|
|
I've been told by Dr. Jack States that most mushroom spores will not survive being eaten by an animal. Mushroom ecology and hypogeous (underground) fungi are his specialties. Along those lines, the spores of truffles and their relatives cannot germinate unless they've been through an animal's digestive system. The cell wall is too thick and needs to be etched by stomach acids. The entire reproductive process for truffles requires animals to spread their spores for them. As you would then expect, no truffles are poisonous.
Largeness is not a good indicator of toxicity. Boletus edulis is one of the larger mushrooms around, and regarded as one of the best edibles by people and animals (deer and squirrels love them). Some of the most poisonous mushrooms are very small, and they don't show up in human poisoning for that reason. People won't bother with a mushroom you'd have to eat 50 of to taste. "Attractive" as I used it means mushrooms which are large enough to be a potential meal, conspicuous enough to find easily, and lacking in vile odors and flavors.
I'm not sure if a young or old Amanita muscaria has higher levels of toxins. I can tell you that squirrels eat them regardless. Dr. States has told me that you could tell when the squirrels had been eating them because they were visibly impaired. He suspects that the toxins in that species are designed to prevent insect larvae from eating them. Perhaps the digestive system of the insects destroys the spores and the squirrels does not.
There does not seem to be any relationship between toxicity and ecological niche. The most dangerous mushroom to people (Amanita phalloides) is mycorrhizal, but the Galerinas and Lepiotas (also very dangerous genera) are primarily saprophytic. Some of the best edible mushrooms are mycorrihzal (Boletus edulis, Chanterelles, Morels (usually they are), Truffles), but saprophytic mushrooms aren't really second best (Agaricus augustus, Oyster mushrooms, Shiitake).
One of the primary reasons mushroom hunting (for food) is considered dangerous by most people is that you must identify each mushroom accurately to keep from being poisoned. With many edible species this is easy, but I often meet people in the forest picking mushrooms to eat that they couldn't possibly be identifying accurately to species (I'm thinking some of the Cortinarius species in particular).
The majority of poisonings occur because of misidentification. Sometimes people rely on folklore, and it turns out not to be very accurate. Others occur with immigrants who confuse a local poisonous species with an edible species they were familiar with in the old country (this is how a lot of Amanita phalloides poisonings occur).
Overall, there are enough different mushrooms in different ecological niches with different toxins that I doubt if any single reason will explain all of them.
--------------------
Happy mushrooming!
|
Nomad
Mad Robot
Registered: 04/30/02
Posts: 422
Last seen: 16 years, 9 months
|
Re: The Visibility of Poison [Re: ToxicMan]
#1311294 - 02/16/03 07:37 AM (21 years, 7 months ago) |
|
|
Very good. Your knowledge blows me away. I knew why I came here... 
Do you have any take on the role of psilocybin among mushroom poisons? Or do you know anything about Dr. States' take on psilocybin, for that matter?
|
ToxicMan
Bite me, it's fun!
Registered: 06/28/02
Posts: 6,731
Loc: Aurora, Colorado
Last seen: 5 hours, 36 minutes
|
Re: The Visibility of Poison [Re: Nomad]
#1312116 - 02/16/03 02:20 PM (21 years, 7 months ago) |
|
|
One possibility is that psilocybin and psilocin are poisonous to some animal (insect?) which would otherwise eat the mushrooms and destroy the spores.
Another idea can be found in this interesting paper mjshroomer posted out here recently. It suggests the idea that production of substances like psilocybin may be a way for the fungus to dispose of excessive amounts of nitrogenous compounds from their habitat.
I have never heard Dr. States say anything about psilocybin or psilocin that I can remember.
--------------------
Happy mushrooming!
|
sancho
mexican
Registered: 12/08/02
Posts: 264
Loc: 20 floors below sea level...
Last seen: 13 years, 25 days
|
Re: The Visibility of Poison [Re: ToxicMan]
#1312339 - 02/16/03 04:37 PM (21 years, 7 months ago) |
|
|
wow. good posts. arent most little brown mushrooms either poisonous or hallucenegenic? i think ive heard that somewhere.......probably wrong though
--------------------
Drugs may be the road to nowhere, but at least they're the scenic route.
|
canid
irregular meat sprocket
Registered: 02/26/02
Posts: 11,912
Loc: looking for zeebras, n. c...
Last seen: 8 months, 27 days
|
Re: The Visibility of Poison [Re: sancho]
#1312375 - 02/16/03 04:57 PM (21 years, 7 months ago) |
|
|
no, but i think the likelihood is greater, and they tend to be more difficult to positively id.
--------------------
 Attn PWN hunters: If you should come across a bluing Psilocybe matching P. pellicolusa please smell it.
If you detect a scent reminiscent of Anethole (anise) please preserve a specimen or two for study and please PM me.
|
ToxicMan
Bite me, it's fun!
Registered: 06/28/02
Posts: 6,731
Loc: Aurora, Colorado
Last seen: 5 hours, 36 minutes
|
Re: The Visibility of Poison [Re: sancho]
#1312445 - 02/16/03 05:15 PM (21 years, 7 months ago) |
|
|
I think most "Little Brown Mushrooms" (LBMs) are unknown. They haven't been tested for toxins. Also, as concretefeet pointed out, they are incredibly difficult as a group to identify. They are difficult enough that David Arora even wrote a short essay on the topic which summarizes to "it is more than just futile for the beginner to attempt to identify them - it is downright foolish." I can identify a few, but generally satisfy myself if I can get them to a genus.
--------------------
Happy mushrooming!
|
|
Threaded
Previous
Index
Next
Edit 
Reply 
Mitchnast
spores
Mycomancer
1 2 all )
oO_wombat_Oo