Nepenthes insignis /nɪˈpɛnθiːz ɪnˈsɪɡnɪs/ is a tropical pitcher plant endemic to New Guinea and surrounding islands.

The specimen, Pulle 277, was collected in southwestern New Guinea at the "[b]order of the Beaufort River"[2] at an altitude of 80 m. It includes male floral material and is deposited at the Bogor Botanical Gardens (formerly the Herbarium of the Buitenzorg Botanic Gardens) in Java.

The specimens, Docters van Leeuwen 10258 and 10286,[3] were collected in northwestern New Guinea at the "[b]order of affluent C of the Rouffaer River"[2] at an altitude of 250 m. They are also deposited at the Bogor Botanical Gardens, although they do not include floral material.

[2] B. H. Danser formally described N. insignis in his seminal monograph "The Nepenthaceae of the Netherlands Indies", published in 1928.

[note a] The description was based solely on herbarium material and Danser did not see the species in its natural habitat.

[2] Two further collections of N. insignis were made by Leonard John Brass in March 1939, 4 km south west of Bernhard Camp, Idenburg River (sheet 13379) and 8 km south west of Bernhard Camp (sheet 13669).

[3] It appears that N. insignis was knowingly observed in the wild only in 1994 by four members of a field trip to New Guinea: W. Baumgartl, B. Kistler, H. Rischer, and A. Wistuba.

Pinnate veins run obliquely towards the margin and are indistinct in the outer part of the lamina.

[5] The pitcher lid is orbiculate to broad cordate, bears a distinct midline, and may be up to 8 cm long.

[4] Numerous large glands are present on the underside of the lid, concentrated near the two main lateral veins.

[2] Upper pitchers gradually arise from the ends of the tendrils, forming a 5 to 35 mm wide curve.

[2] Nepenthes insignis is endemic to Western New Guinea and a number of nearby islands in Cenderawasih Bay.

[6][7] In the southern part of the Lakes Plain region of New Guinea it has been recorded from elevations of between 115 and 800 m. A smaller form of this species is also found near sea-level on the island of Biak.

Plants usually grow epiphytically in thick layers of moss, especially in trees overhanging rivers.

[1][9][10] Relative humidity is always high in these habitats; the seeds of one plant which grew near a small waterfall were found to have germinated while still in their capsules.

It was shown that L-alanine fed in vitro to the pitchers of N. insignis is used to build up plumbagin, but is not incorporated into rossoliside and plumbaside A.

[3] A putative hybrid between N. insignis and N. mirabilis was found by members of the 1994 field trip to New Guinea.

The plant was growing at an altitude of around 500 m.[4] In Papua, N. insignis is commonly sympatric with N. ampullaria and N. maxima, and hybrids involving these species may also occur, although none have been recorded to date.

[6] Folia mediocria sessilia, lamina lineari-lanceolata, nervis longitudinalibus utrinque 4-6, basi in alas 2 decurrente, vagina 0 ; ascidia rosularum ignota ; ascidia caulum breviorum magnitudine mediocria v. maiora, parte inferiore ovata, os versus cylindrica, exalata, costis 2 prominentibus ; peristomio operculum versus acuto, expanso, 2-12 mm lato, costis l/2-3/4 mm distantibus, dentibus minus longis quam latis ; operculo rotundato-ovato, facie inferiore plano ; ascidia superiora magna, e basi lata infundibuliformi subcylindrica v. leviter infundibuliformia, costis 2 prominentibus, peristomio operculum versus acuto v. acuminato, expanso, 8-35 mm lato, costis 1/2-1 mm distantibus, dentibus c. tam longis quam latis ; operculo rotundato-cordato, facie inferiore plano v. plica subcarinato ; inflorescentia racemus longus pedicellis inferioribus c. 20 mm longis omnibus 2-floris ; indumentum in partibus vegetativis subnullum, in inflorescentiis densum adpressum, e pilis stellatis compositum.