Nepenthes tentaculata

Nepenthes tentaculata was formally described by Joseph Dalton Hooker in his 1873 monograph, "Nepenthaceae", Odoardo Beccari (1886), Ernst Wunschmann (1891), Otto Stapf (1894), Günther Beck von Mannagetta und Lerchenau (1895), Jacob Gijsbert Boerlage (1900), Elmer Drew Merrill (1921), and Frederik Endert (1925). John Muirhead Macfarlane's 1908 monograph included a revised description and illustration of the species. Macfarlane also wrote about N. tentaculata in the Journal of the Linnean Society in 1914. An emended Latin diagnosis and botanical description of N. tentaculata were provided by B. H. Danser in his seminal monograph "The Nepenthaceae of the Netherlands Indies", published in 1928. Two infraspecific taxa have been described: • Nepenthes tentaculata var. imberbis Becc. (1886) • Nepenthes tentaculata var. tomentosa Macfarl. (1908) ==Description==

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 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. Nepenthes tentaculata has no indumentum (hairs); all parts of the plant are glabrous. ==Ecology==

Nepenthes tentaculata has a wide distribution that covers Borneo and Sulawesi. It is particularly widespread in the former, where it has been recorded from almost every mountain exceeding 1,000 m. Plants often grow in clumps of Sphagnum moss, spreading vegetatively via creeping subterranean stems. The conservation status of N. tentaculata is listed as Least Concern on the IUCN Red List based on an assessment carried out in 2018. ==Related species==

Nepenthes tentaculata belongs to what has been called the "Hamata group", which also includes four other closely related species from Borneo and Sulawesi: N. glabrata, N. hamata, N. muluensis, and N. murudensis. More recently, N. nigra has joined this group of related taxa. Nepenthes tentaculata is most easily confused with N. muluensis. The lower pitchers of these species are almost identical, but those of N. muluensis have a rounder mouth. The climbing stem, growth habit and leaves are also similar, although N. muluensis usually has a narrower lamina. However, the upper pitchers of N. muluensis are distinctive; they usually have a white lid, a round mouth, and their wings are either greatly reduced or absent altogether. However, a number of populations of N. tentaculata from northern Sarawak produce pitchers exceeding 20 cm in height and these may be very similar in appearance to N. murudensis. Nepenthes murudensis also differs in that its aerial pitchers lack wings. Although N. tentaculata is variable in this respect, plants from Mount Murud usually produce upper pitchers with wings. ==Natural hybrids==

The following natural hybrids involving N. tentaculata have been recorded. • N. burbidgeae × N. tentaculata • N. glabrata × N. tentaculata • N. muluensis × N. tentaculata • N. rajah × N. tentaculata The authors distinguished the taxon from N. muluensis on the basis of its branched spur and the presence of fringe hairs on the top of the lid. They also compared the distribution of phenolic compounds in the leaves of N. muluensis and the hybrid, although they did so without specifying the number of plants studied or the number of repetitions performed. and suggests that the absence of a widely distributed compound like myricetin among the Nepenthes examined might provide additional diagnostic information for these taxa. ==Notes==