The specific epithet lingulata is derived from the Latin word lingula, meaning "small tongue", and refers to this unique morphological feature.

The first collection of the species was made on April 22, 2005, south of Padang Sidempuan in the Indonesian province of North Sumatra.

A pair of wings (≤2.5 mm wide) with fringe elements up to 1 cm long runs down the front of the pitcher.

A single filiform appendage (≤4 cm long) hangs over the pitcher mouth, the apical end of which is covered with scattered raised nectar glands.

[1] A very dense indumentum of long woolly grey-brown hairs is present on immature tendrils and the outer surface of pitchers.

[2] Many Nepenthes species, including the closely related N. izumiae, have a glandular crest on the underside of the lid.

[1] Nepenthes lingulata is also unusual in that the undersurface of the lid is completely devoid of glands, except for a small group concentrated at the end of the tongue-like appendage.

[1] A similar trapping method is employed by the Bornean endemic N. bicalcarata, which has a pair of spines positioned over the pitcher mouth.

[1][4][5] Nepenthes lingulata is thought to be most closely related to N. izumiae, with which it shares the general morphology and colouration of its pitchers.

However, it can be easily distinguished from that species on the basis of the highly developed filiform appendage that hangs over the pitcher mouth.

Furthermore, N. lingulata completely lacks nectar glands on the underside of the lid and has a very dense woolly indumentum.

[1] Nepenthes lingulata is more distantly related to the Sumatran species N. densiflora, N. diatas, N. singalana, and N. spathulata.

— Typus: Lee, Hernawati, Akhriadi NP 432 (holo ANDA), Indonesia, Sumatera Utara, Bukit Barisan, south of Padang Sidempuan, 22 April 2005.