Nepenthes longifolia () is a tropical pitcher plant endemic to Sumatra, where it grows at elevations of between 300 and 1100 m above sea level. The specific epithet longifolia, formed from the Latin words longus (long) and folius (leaf), refers to the exceptionally large leaves of this species. Botanical history The first known collection of N. longifolia was made by Willem Meijer in 1957. The specimen Meijer 6913 was collected on August 24, 1957, in a sandstone region of the river Tjampo near Taram in West Sumatra, at an altitude of 500–1000 m. The plant was growing in forest on the slope of a river valley. The specimen is sheet H.L.B. 958.85111 at the National Herbarium of the Netherlands in Leiden. In 1986, Rusjdi Tamin and Mitsuru Hotta invalidly described Nepenthes rafflesiana var. longicirrhosa. Charles Clarke observed this taxon at the type locality in 1995 and concluded that it is conspecific with N. longifolia. Subsequent revisions of the genus have formally synonymised these taxa. Nepenthes longifolia was formally described by Joachim Nerz and Andreas Wistuba in a 1994 issue of the Carnivorous Plant Newsletter. The holotype of N. longifolia, Nerz 2801, was collected by Joachim Nerz on September 25, 1992, in the Tjampo Mountains near Taram, West Sumatra, at an altitude of 1000 m. It is deposited at the National Herbarium of the Netherlands in Leiden. Seven other specimens of N. longifolia were collected on the same day and at the same location; Nerz 2802, 2803, 2804, and 2805 are deposited at the National Herbarium of the Netherlands (L) together with the holotype, while Nerz 2806, 2807, and 2808 are held at the Institut für Biologie I at the University of Tübingen (TUB) in Germany. Matthew Jebb and Martin Cheek treated N. longifolia in synonymy with N. sumatrana in their 1997 monograph, "A skeletal revision of Nepenthes (Nepenthaceae)". The authors tentatively upheld this synonymy in their 2001 revision, "Nepenthaceae", writing: Although we treat N. longifolia as a synonym [of N. sumatrana], it is representative of other specimens from inland Sumatra, at higher altitudes (c. 1000 m) that show differences from the plants at sea level on the coast. The inland plants have more slender pitchers which are ellipsoid in the lower half and cylindrical in the upper (not infundibuliform), with an elliptic (not a suborbicular) lid. However, intermediates are reported. More specimens are needed before N. longifolia can be fully