Nepenthes adnata

Nepenthes adnats is a tropical pitcher plant endemic to the Indonesian province of West Sumatra, where it grows at elevations of 600 to 1200 m above sea level. The specific epithet adnata is Latin for "broadly attached" and refers to the base of the lamina.

Nepenthes adnata was first collected by Willem Meijer on August 24, 1957. The holotype, Meijer 6941, was collected on that date near the river Tjampo, east of Payakumbuh, Taram, West Sumatra, at an elevation of 1000 m. It is deposited at the National Herbarium of the Netherlands in Leiden.
The species was first described in 1986 by Mitsuru Hotta and Rusjdi Tamin based on specimens the authors collected near Harau in West Sumatra. However, the description was invalid as it lacked a Latin diagnosis. This was provided eight years later by Jan Schlauer.

Nepenthes adnata is a diminutive species. The stem is cylindrical in cross section and may be climbing or drooping. It rarely exceeds 2 m in length and 3 mm in diameter. Internodes are up to 10 cm long.

Leaves are coriaceous and sessile. The lamina is lanceolate-ellipsoidal and may be up to 10 cm long and 2 cm wide. It has an adnate base and an obtuse to acute apex. Two to three longitudinal veins are present on either side of the midrib. Pinnate veins are not easily distinguished. Tendrils may be up to 5 cm long.

Rosette and lower pitchers are ovoid in the lower third and cylindrical above. They are small, reaching only 10 cm in height and 2.5 cm in width. A pair of fringed wings (≤3 mm wide) runs down the front of terrestrial pitchers. The glandular region covers only the lower third of the inner pitcher surface. The pitcher mouth is round and slightly oblique throughout. The cylindrical peristome is up to 2 mm wide and bears indistinct teeth. The peristome is roughly symmetrical in cross section, with the inner portion accounting for around 54% of its total cross-sectional surface length. The lid or operculum is orbicular and cordate at the base. Multicellular hairs are sometimes present on its upper surface. An unbranched spur (≤2 mm long) is inserted at the base of the lid.

Upper pitchers are ovoid in the lower quarter and cylindrical to infundibular above. In aerial pitchers, the wings are usually reduced to ribs, but sometimes bear fringe elements. In most other respects, they are similar to lower pitchers.