荷属东印度群岛的猪笼草科植物
In 1928, B. H. Danser published his seminal monograph, "The Nepenthaceae of the Netherlands Indies", in which he divided "Nepenthes" into six clades, based on observations of herbarium material. The clades were: the "Vulgatae", "Montanae", "Nobiles", "Regiae", "Insignes" and "Urceolatae". Danser placed "N. rajah" in the "Regiae" (Latin: pl. of "rēgia": royal). The "Regiae" clade as proposed by Danser is shown in the adjacent table.