- Wilting cherry leaves have cyanide in them--enough, in fact, to kill large livestock.
- Gila monsters have a venomous bite, which has occasionally been fatal.
- The dogbane plant, which makes strong cordage, contains a toxic cardiac glycoside, apocynamarin, which can cause a heart attack if ingested.
- A common wild plant called Mexican tea, also known as epizote, is commonly used as a cooking herb; however, it is toxic enough to expel worms and it can be fatal in large doses.
- Mistletoe is an oak tree parasite plant, which gets a lot of attention around Christmas and has claimed the lives of both people and animals.
- The false morel mushroom is quite poisonous, with recorded fatalities and a disturbingly similar appearance to the popular edible morel.