Nepenthes rafflesiana, or Raffles' pitcher-plant, is a species of tropical pitcher plant. It has a very wide distribution covering Borneo, Sumatra, Peninsular Malaysia, and Singapore. Nepenthes rafflesiana is extremely variable, with numerous forms and varieties described. In Borneo alone, there are at least three distinct varieties. The giant form of this species produces enormous pitchers rivalling those of N. rajah in size.

Nepenthes rajah is a carnivorous pitcher plant species of the family Nepenthaceae. It is endemic to Mount Kinabalu and neighbouring Mount Tambuyukon in Sabah, Malaysian Borneo. Nepenthes rajah grows exclusively on serpentine substrates, particularly in areas of seeping ground water where the soil is loose and permanently moist. The species has an altitudinal range of 1,500–2,650 metres (4,920–8,690 ft) a.s.l. and is thus considered a highland or sub-alpine plant. Due to its localised distribution, N. rajah is classified as an endangered species by the IUCN and listed on CITES Appendix I.