Tropical plants are popularly grown as houseplants. Most feature large, variegated or colorful leaves that make them attractive decor choices. They also thrive in the warmth of the indoors. The downside of these beautiful plants is that many of them are poisonous. Some can harm humans, while others are toxic to cats and dogs. Some are entirely poisonous, while others contain toxic parts, such as seeds, but are otherwise harmless. Take care when handling these pretty plants.
Caladium (Caladium Spp.)
Caladium plants are popular for their brightly colored, huge, heart-shaped leaves. Often called "Elephant Ear" plants, caladiums are commonly given as gifts. The leaves and stems of the plant contain calcium oxalate, which can cause the mouth, tongue and throat to swell up if ingested. Nausea and vomiting are also symptoms of ingesting the toxin. While not life-threatening, these symptoms are painful.
Philodendron (Philodendron Spp.)
Philodendron plants also contain oxalates. The milky-white sap of the plant can cause the skin to become red, swollen and itchy. If the leaves are chewed, the lips and tongue can swell up.
Cardboard Palm (Zamia Furfuracea)
The cardboard palm is a small, bushy palm often grown in containers indoors. The plant has thick, plastic-like leaves and thorny stems. All parts of the plant are poisonous, but the roots and seeds are particularly toxic and can cause liver and kidney failure in pets. This slow-growing plant takes several years to flower, so the poisonous seeds are not usually a problem.
Crotons (Croton Spp.)
Crotons are another popular foliage plant. They feature colorful leaves, often with strong veining patterns. The sap and leaves of these plants contain toxins that may cause diarrhea or vomiting. They also contain oxalate crystals, which will cause pain in the mouth and stomach if ingested, as well as some swelling.
Oleander is sometimes grown as an indoor plant, although it is planted outdoors in the majority of cases. It is worth mentioning, however, because it is one of the most toxic garden plants in the world. Oleander is extremely poisonous, according to Denver Plants. Ingesting the leaves of this plant can be fatal to a child or pet, and even chewing on the leaves may be enough to send a small child to the hospital. For that reason, it is not recommended for cultivation in homes or home gardens with children or pets.