As a herbalist I will share some wisdom when it comes to knowing if a plant is poisonous, now this isn't always the rule but this is definitely a good tell-tale sign. A flower that is transparent, limpy in structure, and droopy is most likey poisonous. There has been plants that I didn't specifically know what it is but knew based off of the plants appearance and what I could see for family characteristic they have ended up in fact being poisonous. Also plants aren't out to trick you. What you pick up and/or what you observe about a plant is your intuition telling you what it is that you see.