Are Begonias Poisonous To Humans?

Are Begonias Poisonous To Humans? Are begonias poisonous to humans? Begonia – This pretty flowering plant is toxic to both people and animals. The underground parts of wax begonias are poisonous. Meanwhile, tuberous begonias have toxin in their tubers. Are begonias poisonous? Begonias contain calcium oxalate. This crystalline substance is mildly toxic, but very irritating