Philodendron is a large genus of flowering plants in the Araceae family. As of September 2015, the World Checklist of Selected Plant Families accepted 489 species other sources accept different numbers. Regardless of number of species, the genus is the second-largest member of the Araceae family.[citation needed] Taxonomically, the genus Philodendron is still poorly known, with many undescribed species. Many are grown as ornamental and indoor plants. The name derives from the Greek words philo- or "love, affection" and dendron or "tree". They are commonly called by their generic name.