Nepenthes neoguineensis

Nepenthes neoguineensis is a climbing plant. The stem is up to 6 mm thick and cylindrical to obtusely angular in cross section, especially in the upper part of the internodes. Internodes are up to 4 cm long.

Leaves are chartaceous and petiolate. The lamina is lanceolate and reaches 25 cm in length and 4.5 cm in width. It has an acute apex and is gradually or rather abruptly attenuate towards the base. Three or four indistinct longitudinal veins are present on either side of the midrib. Pinnate veins ascend obliquely from the midrib and are irregularly reticulate in the outer part of the lamina. Tendrils are up to 4 mm thick and about as long as the lamina. Upper pitchers gradually arise from the ends of the tendrils, forming a 7 to 23 mm wide curve. They are infundibulate in the lower part, somewhat ventricose at two-fifths of their height, and widened towards the mouth. A pair of fringed wings (≤8 mm wide) runs down the entire length of the pitcher. The pitcher mouth is oblique and acuminate towards the lid. The peristome is cylindrical or flattened and up to 1.5 mm wide. The glandular region covers the lower third of the inner surface of the pitcher. The glands occur at a density of about 700 to 900 per square centimetre. The lid is suborbicular, truncate or slightly emarginate, and rounded or slightly cordate at the base. …

Nepenthes neoguineensis is native to New Guinea and the nearby D'Entrecasteaux Islands, and may also occur on Misool (see N. sp. Misool). The species is relatively widespread in New Guinea, ranging across the entire length of the island and occurring in both Papua New Guinea and the Indonesian portion of the island (Western New Guinea). As such, its conservation status is listed as Least Concern on the 2006 IUCN Red List of Threatened Species. Nepenthes neoguineensis grows on river edges, river gravel bars, ridge crests, and rarely in open grassland or disturbed forest. It has a wide altitudinal distribution, occurring from sea-level to an elevation of 900 m (3,000 ft), occasionally 1,400 m (4,600 ft). In the wild, N. neoguineensis occurs sympatrically with N. ampullaria and N. maxima.

Nepenthes neoguineensis was first collected in 1828 by Alexander Zipelius near Triton Bay, New Guinea.[note a] Two further collections were made by Gerard Versteeg on June 19[note b] and September 25, 1907.[note c] N. neoguineensis was again collected on May 10, 1910, by Knud Gjellerup.[note d] The first name applied to this species was Nepenthes leptoptera by Hermann Zippel in 1900. However, this name is not valid as it only appeared on the label of a herbarium specimen (HLB.908.154-597) deposited at the National Herbarium of the Netherlands in Leiden. The specimen was collected from New Guinea. Nepenthes neoguineensis was described by John Muirhead Macfarlane in 1911 based on the specimen Versteeg 1746, which consists of female plant material. In 1916, Henry Nicholas Ridley described what he believed represented a male plant of N. neoguineensis. However, in his seminal monograph "The Nepenthaceae of the Netherlands Indies", B. H. Danser showed that it belonged to a closely related but distinct species, which he named N. papuana.[note e]