Fringed pitcher-plant (Nepenthes tentaculata)

Description

Nepenthes tentaculata /nɪˈpɛnθiːz tɛnˌtækjuːˈlɑːtə/, or the fringed pitcher-plant,] is a tropical pitcher plant with a wide distribution across Borneo and Sulawesi. It grows at altitudes of 400–2550 m. The specific epithet tentaculata is derived from the Latin word tentacula, meaning "tentacles", and refers to the multicellular appendages on the upper surface of the pitcher lid. Nepenthes tentaculata is a climbing plant. The stem may reach a length of 3 m and is up to 5 mm in diameter. Internodes are circular to triangular in cross section and up to 10 cm long. The leaves of this species are sessile. The lamina or leaf blade is lanceolate to elliptic in shape and up to 15 cm long by 3 cm wide. Its apex is rounded to acute, while the base is amplexicaul and cordate, encircling the stem. Up to 4 longitudinal veins are present on either side of the midrib. Pinnate veins are irregularly reticulate. Tendrils are up to 15 cm long. The pitchers of N. tentaculata are generally quite small, rarely exceeding 15 cm in height. However, in exceptional specimens they may be up to 30 cm high by 8 cm wide. Rosette and lower pitchers are ovoid in the basal third and cylindrical above. Upper pitchers are more cylindrical throughout. A pair of fringed wings runs down the front of lower pitchers, while in upper pitchers these are often reduced to ribs. The pitcher mouth is usually ovate, becoming acute at the front and rear. Its insertion very oblique. The peristome is roughly cylindrical in cross section and up to 5 mm wide. It bears small ribs and its inner margin is lined with tiny teeth.The inner portion of the peristome accounts for around 57% of its total cross-sectional surface length. The pitcher lid or operculum is ovate and typically obtuse. Often, numerous filiform appendages are present on the upper surface of the lid, concentrated near the edge.However, some forms of the species lack these structures altogether. Nepenthes tentaculata has a racemose inflorescence. The peduncle is up to 15 cm long and the rachis up to 10 cm long, although female inflorescences are generally shorter than male ones. Pedicels are bract-less and reach 10 mm in length. Sepals are oblong-lanceolate in shape and up to 3 mm long. A study of 210 pollen samples taken from a herbarium specimen (Mjöberg 49, collected in Borneo at an altitude of 1700 m) found the mean pollen diameter to be 29.8 μm (SE = 0.4; CV = 9.4%). Nepenthes tentaculata has no indumentum (hairs); all parts of the plant are glabrous.