Nepenthes muluensis was first collected by Mitsuru Hotta on March 18, 1964, on Mardi between the third and fourth camps on the western ridge of Mount Mulu, Sarawak.
Nepenthes muluensis has been misidentified at least once in the literature; Bertram Evelyn Smythies identified specimens of N. muluensis as belonging to N. gracillima,[REF] a species endemic to Peninsular Malaysia.