A philodendron is a tropical plant often used as a houseplant. As of September 2015, the World Checklist of Selected Plant Families recognized 489 species of philodendron. The WCSP is maintained by the Royal Botanic Gardens, Kew, in London.
Philodendrons come in vining and non-climbing varieties. Blushing and heartleaf philodendrons are examples of vining philodendrons. Lacy tree and birds nest philodendrons are two non-climbing varieties. Depending on the species, philodendron leaves are oval-, spear- or heart-shaped and are usually waxy and shiny. The leaves are toxic to pets and children.
Gardeners consider philodendrons easy to grow indoors. They should be placed in indirect sunlight, and they can be moved outdoors during mild weather. A National Aeronautics and Space Administration study from the 1980s determined that philodendrons are beneficial for indoor air quality.