The evidence for whether climbing aroid is poisonous is patchy, however, many species of the Pothos genus are poisonous, so take extra caution here. The leaves and stems tend to contain toxic compounds called calcium oxalate crystals that mimic the feel of glass shards when ingested. Eating Pothos plants typically causes irritation of the lips, tongue and throat, and may result in vomiting. In extreme cases, you may have difficulty breathing because of irritation to the respiratory system. Avoid direct contact with this plant as it's likely to cause skin irritation. Children are the usual victims of Pothos poisoning as it's a popular houseplant, and children love to put new and interesting-looking things in their mouths!