Nepenthes sumatrana

Nepenthes sumatrana produces sub-cylindrical climbing stems up to 15 m long and 0.9 cm thick. These have internodes up to 20 cm long. Leaves are coriaceous and petiolate. The lamina is lanceolate-obovate in form and grows to 55 cm in length and 9 cm in width. Longitudinal veins are present in 6–8 pairs together with numerous pinnate veins. Tendrils are up to 60 cm long.

Rosette pitchers may be ovoid throughout or narrowly ovoid in the lower half and cylindrical above. They grow up to 10 cm high and 4 cm wide. Two fringed wings, up to 8 mm wide, run along the front of rosette pitchers. The peristome is cylindrical in cross-section and up to 4 mm wide, bearing indistinct teeth. The pitcher lid or operculum is sub-orbiculate and has no appendages. An unbranched spur (≤15 mm long) is inserted at the base of the lid. Lower pitchers are wholly ovoid, with the hip located just below the peristome. They grow to 20 cm high and 10 cm wide, and possess a pair of fringed wings up to 6 mm wide. The peristome is cylindrical in cross-section and up to 10 mm wide. The lid is orbiculate and, as in rosette pitchers, bears an unbranched spur. Upper pitchers are infundibular (funnel-shaped) throughout. They are by far the largest of the traps produced by this species, reaching 30 cm in height and 15 cm in width. As in many Nepenthes species, the wings are reduced to ribs in aerial pitchers. …

Nepenthes sumatrana is endemic to the Indonesian provinces of North Sumatra and West Sumatra. It is best known from the hills around Sibolga, where it was first collected. The species has a patchy distribution and the full extent of its geographical range is uncertain. Specimens collected near Sawahlunto and named Nepenthes spinosa by Tamin and Hotta[note c] appear to be conspecific with N. sumatrana, although trips to the area in 1995 and 2001 failed to locate any plants. Nepenthes sumatrana grows terrestrially in dense, undisturbed lowland forest on sandstone substrates. Moist, shady conditions appear to be vital to the survival of the species, as it has not been recorded from areas that have been cleared due to logging or agricultural activities. These requirements might explain the fragmented nature of its distribution and suggest that N. sumatrana is more seriously threatened with extinction than previously thought. Plants are often found on very steep slopes. Seedlings of N. sumatrana have been recorded from open cliff faces, but it is uncertain whether these survive to maturity, as larger plants are only known from the forests, where their stems can use surrounding objects for support and climb into the canopy. Nepenthes sumatrana has been recorded from elevations of between 0 and 800 m above sea level.