Are mushroom identification questions in scope?
Let's assume the question may or may not be in the context of a person's garden or soft landscaping project.
I notice too there is a dead mycology proposal in Area 51, so there does not appear to be an SE place to redirect such questions.
I would say they're off-topic (others, please leave an answer if you have an alternate view point or upvote if you agree).
The average gardener (or even experienced ones) is not a mycologist and will probably not know the different types of mushrooms and their properties. They're mostly just interested in recognizing it as one and inferring that it could be a source of dampness/rotting wood, etc. and take action accordingly (or not).
Identifying mushrooms requires highly specific expertise and there are no clear visual distinctions between edible and poisonous mushrooms, which makes the problem all that more harder. Given that our audience will not have the said expertise and the potential harm that could arise out of incorrect identifications, I'd strongly suggest also making it clear in the FAQ that it is off-topic.
The absence of a Stack Exchange site to ask questions on a particular topic is not a good enough reason to ask it on a site where it is only tangentially related.
Some notes from the Wikipedia article on mushrooms on the difficulty in identifying them:
More generally, and particularly with gilled mushrooms, separating edible from poisonous species requires meticulous attention to detail; there is no single trait by which all toxic mushrooms can be identified, nor one by which all edible mushrooms can be identified.
There are a number of species of mushroom that are poisonous and, although some resemble certain edible species, consuming them could be fatal. Eating mushrooms gathered in the wild is risky and should not be undertaken by individuals not knowledgeable in mushroom identification, unless the individuals limit themselves to a relatively small number of good edible species that are visually distinctive.
We don't need a blanket ban on mushrooms.
I don't see why mushroom identification should be out of scope:
If you change "mushroom" in the question to "fruiting shrub", does it change whether it is in scope? I don't think so.
We've had some identification questions that are probably out of scope. I remember a tree (in Spain?) that had little to do with someone's home garden/landscape, it was primarily a curiosity.
I agree. I would hate to give an opinion that results in poisoning or death.
I can see both points of view and have mushroom identification questions of my own that I've been mulling over (every time I see a new kind pop up in the backyard in fact).
First I thought...
Cooking?
Given that you're not so much identifying the species but whether they're edible or not (or how edible) then perhaps such questions genuinely belong on the Cookery SE, even though the members here are probably more likely to be able to answer.
As an aside, check out the bottom answer on this question: https://cooking.stackexchange.com/questions/3225/how-can-i-tell-if-a-mushroom-is-poisonous
Then I thought...
Biology?
If you want a positive species identification then arguably the newly minted Biology SE could even be a valid target for such questions.
Then I concluded...
Not appropriate anywhere?
Even so, regardless of which SE should be the target for the question, maybe a generic Stack Exchange (like Gardening, Cookery, Biology) is simply not the right way to go about identifying a mushroom for consumption and so should actively be discouraged across all 3 SEs.
If a "mushroom identification" SE ever gets off the ground I'll be in there for sure.
New Area 51 proposal: http://area51.stackexchange.com/proposals/41570/mushroom-identification
Actually, I had a crack at it -- anyone wish to hop on board or help me with a better description/title?
