Dieffenbachia
Pets and small children need to be extremely careful around dieffenbachia, one of the most poisonous plants you’ll find in your backyard. Taking a big bite out of one of the leaves of this plant will make them extremely ill. Symptoms include oral pain, vomiting, and decreased appetite. This is due to the insoluble calcium oxalate crystals in the leaves. If the skin or eyes are exposed, redness, swelling, and irritation may occur. The poison comes from the raphides, which are tiny, needle-like structures that may cause respiratory distress. Even though this makes a great house plant, you need to be very careful not to ingest it (Best Life Online).