Nepenthes eustachya from Sumatra was once considered to fall within the variability of N. alata, but this was based on a misinterpretation of type specimens; these two species do not seem closely related to each other.
Nepenthes eustachya dari Sumatera pernah dianggap termasuk ke dalam variabilitas N. alata, tetapi didasarkan pada jenis spesimen salah tafsir, dua spesies ini tampaknya tidak terkait erat satu sama lain.