Nepenthes bicalcarata

Nepenthes bicalcarata (/nɪˈpɛnθiːz baɪˌkælkəˈrɑːtə/ or /bɪˌkælkəˈreɪtə/; Latin: bi 'two', calcaratus 'spur'), also known as the fanged pitcher-plant, is a tropical pitcher plant endemic to northwestern Borneo, Indonesia. It is a myrmecophyte noted for its mutualistic association with a species of ant, Camponotus schmitzi. As an ant-fed plant it lacks many of the features that characterise the carnivorous syndrome in Nepenthes, including viscoelastic and highly alkaline pitcher fluid, the waxy zone of the pitcher interior, and possibly even functional digestive enzymes. Nepenthes bicalcarata was formally described by Joseph Dalton Hooker in his 1873 monograph, 'Nepenthaceae', based on specimens collected by Hugh Low and Odoardo Beccari near the Lawas River in Borneo. The type specimen, Low s.n., is deposited at the Royal Botanic Gardens, Kew. Seven years later, Spencer Le Marchant Moore described Nepenthes dyak, based on a specimen (Teijsmann 10962) collected by Johannes Elias Teijsmann from Kapuas River near Sintang in western Borneo. This specimen is also held at the Royal Botanic Gardens, Kew and a duplicate is deposited at the National Herbarium of the Netherlands in Leiden. Nepenthes dyak was later mentioned several more times in the botanical literature, but is now considered conspecific with N. bicalcarta. Nepenthes bicalcarata was introduced to Europe in 1879 by British explorer Frederick William Burbidge, who collected plants for the famous Veitch Nursery. These were cultivated to larger size and distributed in 1881. During this time, interest in Nepenthes had reached its peak. A note in The Gardeners' Chronicle of 1881 mentions the Veitch Nursery's N. bicalcarata as follows: Several years after its introduction, N. bicalcarata was still very much a horticultural rarity. In Veitch's catalogue for 1889, N. bicalcarata was priced at £3.3s per plant, while the famous giant-pitchered N. northiana and N. rajah were selling for £2.2s. Nepenthes bicalcarata plants are the largest in the genus, climbing up to 20 m into the forest canopy. The cylindrical stem is thicker than that of any other Nepenthes species, measuring up to 3.5 cm in diameter. Internodes are up to 40 cm long. The leaves of N. bicalcarata are petiolate and coriaceous in texture. The lamina is obovate-lanceolate in form and also reaches huge dimensions, growing to 80 cm in length and 12 cm in width. It is slightly decurrent on the stem, forming two narrow wings. The lamina has indistinct longitudinal veins and numerous pennate veins. Tendrils may be up to 60 cm long and 8 mm wide. They are hollow and swollen near the pitcher. Although most parts of the plant are very large, the pitchers themselves do not rival those of species such as N. rajah. Nevertheless, they may have a volume of over one litre and grow up to 25 cm high and 16 cm wide. A pair of prominent fringed wings (≤15 mm wide) runs down the front of lower pitchers. These are usually reduced to ribs in aerial pitchers. The peristome (≤20 mm wide) is characteristically flattened and curved inwards. The inner portion of the peristome accounts for around 70% of its total cross-sectional surface length. It bears small but distinct teeth. The two sharp spines for which the species is famous are present on the underside of the pitcher lid, and may be 3 cm long. They are derived from the uppermost 10–12 peristome ribs. The pitcher lid or operculum is reniform to cordate and has no appendages. An unbranched spur (≤15 mm long) is inserted at the base of the lid.