Also known as tropical pitcher plants or monkey cups, is a genus of carnivorous plants in the monotypic family Nepenthaceae. The genus comprises roughly 150+ species, and numerous natural and many cultivated hybrids. The greatest diversity of natural populations occurs on Borneo, Sumatra, and the Philippines. Many grow in warm, humid, lowland areas, but the majority are tropical montane plants, receiving warm days and cool to cold, humid nights year round. A few are considered tropical alpine, with cool days and nights near freezing. The name “monkey cups” refers to the fact that monkeys have been observed drinking rainwater from these plants.