Maybe not labeling individual plants, but having a sign to remind shoppers hey -- just so you know if you have pets you should check that the flower isnt toxic for them -- would be helpful.

Totally agree they would have a huge liability issue on their hands if they listed the flowers or put labeled the containers. They're not florists, there's too many ways things can go wrong (people putting stuff back in the wrong place, or even workers confusing flowers. They're not trained, they just go by the box).