Yes. Honey made predominantly from rhododendrons is very toxic as it contains grayanotoxins,. It can result in "mad honey disease." Human death is very unlikely.
The pollen of oleander is also toxic and can lead to toxic honey.
> Do we owe our lives to fungi?
Without fungi. there are other decomposers such as bacteria and archaea to carry on that part of the biogeochemical cycles.
Without fungi, plants would have developed better roots.
Many fruit and vegetables have been modified, either genetically or through selective breeding. Here are some good examples of that, which also includes bananas - http://uk.businessinsider.com/foods-before-genetic-modification-2015-8
that grow really fast and resistant to insects.
that way they can preserve the natural environment by having a small area for these trees
They do elevated levels of C02 promote more vigorous plant growth and thus an enhanced absorbtion of C02. Well they take up some of it anyway probably much more than the Climate Change religion wants us to know about.
Where I live it's like snowing these things from the cottonwood trees, I don't know where these trees are even.
Do you have them where you live?