Dusky pitcher-plant (Nepenthes fusca)

Description

Nepenthes fusca /nɪˈpɛnθiːz ˈfʌskə/, or the dusky pitcher-plant, is a tropical pitcher plant endemic to Borneo. It is found throughout a wide altitudinal range and is almost always epiphytic in nature, primarily growing in mossy forest. The specific epithet fusca is derived from the Latin word fuscus, meaning "dark brown" or "dusky", and refers to the colour of the pitchers. Nepenthes fusca is a climbing plant. The stem may attain a length of 10 m and is up to 8 mm in diameter. Internodes are circular in cross section and up to 7 cm long. The leaves of this species are petiolate and coriaceous in texture. The lamina or leaf blade is obovate-oblong in shape and measures up to 15 cm in length by 6 cm in width. Its apex is acute to obtuse and may even be slightly peltate. The base of the lamina is gradually attenuate towards the petiole. The petiole (≤4 cm long)\ is grooved lengthwise and bears a pair of narrow wings that form a semi-amplexicaul sheath around the stem. Up to 3 longitudinal veins are present on either side of the midrib,\ although they are indistinct. Pinnate veins are numerous. Tendrils measure up to 5 cm in length. Rosette and lower pitchers are cylindrical throughout. They usually grow to 20 cm in height by 4 cm in width, although exceptional specimens up to 28 cm have been recorded.A pair of fringed wings (≤5 mm wide) runs down the ventral surface of the pitcher and bears fringe elements measuring up to 10 mm and spaced 6 mm apart. The glandular region is restricted to the lower portion of the pitcher's inner surface. The glands are small, overarched, and occur at a density of 600 to 650 per square centimetre. The waxy zone is reduced. The pitcher mouth is positioned horizontally at the front, becoming elongated into a neck at the rear. The peristome is flattened and expanded (≤12 mm wide), but bears only indistinct teeth (≤0.3 mm long) The inner portion of the peristome accounts for around 51% of its total cross-sectional surface length.The pitcher lid or operculum is very narrowly ovate in shape and has a distinctive basal crest on its lower surface. An unbranched spur measuring up to 10 mm in length is inserted near the base of the lid.