"Sir Joseph Hooker (1873) wrote enthusiastically of this plant: "This wonderful plant is certainly one of the most striking vegetable productions hither-to discovered, and in this respect is worthy of taking place side by side with the Rafflesia arnoldii, it hence bears the title of my friend Rajah Brooke, of whose service in its native place it may be commemorative among botanists." As rajah means ruler or king, it has been called by some the "King of Nepenthes". Many stories are woven around this plant. It probably has the largest pitchers, and both Phillipps and Lamb (1996) and St. John (1862) observed drowned rats in a pitcher with a capacity of more than two litres. This plant grows only in Sabah, on Mount Kinabalu at 1500-2600 m and Mount Tambuyukon, and seems to prefer humid zones and land slips. There are many hybrids of N. rajah, perhaps because this species flowers at any time of the year, and, with the exception N. lowii, all species on Mount Kinabalu seem to have hybridised with N. rajah. We found these huge plants on the slopes of the Mesilau Valley northeast of Kinabalu Park Headquarters, a grassy region near a waterfall, therefore providing quite a humid microclimate."