Ana, I think you are right. I certainly don't intend to stop gardening because of some plants being poisonous! And yeah, having raised children, I well know that the little darlings will put *anything* in their mouths. It's something that one needs always to bear in mind.
Thorny, I agree that a lot of people, cityfolk in particular, are totally unaware even of the concept of poisonous plants, and many others have mistaken beliefs about how to determine whether or not something is poisonous: with flowering plants they often believe that things that taste nice are okay, that particular colours or shapes are always safe or unsafe, that cooking always destroys toxins, or that anything you see being eaten by a bird or animal is safe to eat. All of these ideas are utterly wrong.
One of the things I do IRL is teach foraging and wildcrafting, including examining and certifying the skills of those foragers who collect ingredients for wild food and bush-tucker restaurants in my area, so I do my best to keep my knowledge base active and up to date. But there will always be those who are careless or stupid in such matters. With fungi in particular, accurate identification is absolutely crucial, because many of the really deadly ones, such as death caps, are pleasant tasting, as are such things as the berries of potatoes and deadly nightshade (belladonna).
Sc0ut: I think thorny is right that JoB may not know what you do and don't know, and I would add that 'pedant' seems to be what he does, and is in his nature - I don't think he means to be nasty. As a well-meaning information nerd myself, I sometimes get misinterpreted the same way!
Iris leaves can also be poisonous, but people and animals seldom eat them because of the fibrous texture and unpleasant taste; the rhizomes are a little easier to eat because not quite so stringy and tough, though still not something one would eat unless one were a dog or a small child.
Something else I should have mentioned: many botanic gardens and some museums maintain databases of poisonous plants, many of which are accessible to the public. Does your country have a Museum of Economic Botany or equivalent? Might be worth looking online for such, or visiting and asking for information sheets if they have such. I know that the Adelaide and Melbourne Botanic Gardens, as well as the National Botanic Garden in Canberra, do publish such information, which may be of more use to you than you might think, since being Botanic Gardens they have a lot of information on European plants as well as local ones. Many sites dedicated to foraging and wild food also contain such information, especially about poisonous plants similar enough in appearance to edible ones that mistakes may occur.
That link you put up is interesting, thanks! I knew about the role of bird digestion in dispersing and breaking dormancy for some seeds, because it is an issue that sometimes comes up in the groups I belong to which propagate rare food plants. One of the things we work on is how to germinate the seeds of plants of which the bird symbiont is now rare or extinct, or not to be found in our area. Quandong and sandalwood seeds aren't too hard, soaking and exposure to heat will often serve in the stead of the digestive tract of an emu, which is what they use in the wild. Something I am working on at present is the germination of Acrotriche seeds, Acrotriche plants being notoriously difficult to propagate in captivity. I was talking to a very old lady whose grandparents were among the pioneers of the Adelaide Hills about the many healthy and productive Acrotriche plants on her property (they are rare and slow-growing), and she mentioned that they came up spontaneously wherever her dad had dumped the residue from his homebrewing when she was a kid. He brewed a fruit wine from the berries, and something in the fermenting process stimulated germination of the seeds, which normally depend on the digestion of birds and small marsupials such as bandicoots and bilbies. She gave me a couple of kilos of the fruit, which I shared with several interested folk, and we are trying different fermentation methods to see what gives the best results. Sorry to go off at a tangent, but thought this might interest you.
I have a couple of European books with information about poisonous wild and garden plants, I'll try to track down titles and authors.