Some common house plants that are toxic to cats include dieffenbachia, cyclamen, aloe vera, asparagus ferns and elephant ear plants. Lilies, including Easter lilies and calla lilies, are especially dangerous for cats.
If a cat ingests part of a toxic houseplant, possible reactions include vomiting, irritation around the mouth, diarrhea, drooling or death. Some toxic plants are only dangerous if the cat consumes a particular part of the plant, such as the flower, stem, leaves or berries. Other species have toxins throughout the whole plant. Cat owners with potentially toxic houseplants should keep those plants out of reach to prevent accidental poisoning.