Nepenthes fusca

The first known collection of N. fusca was made by Frederik Endert on October 12, 1925, from Mount Kemul in East Kalimantan, at an elevation of 1,500 m. It was discovered during an expedition to central Borneo by the Forest Research Institute of Bogor (then known as Buitenzorg), Endert wrote about this pitcher plant in a detailed 1927 account of the expedition, Matthew Jebb does not consider these differences significant enough to merit distinction at the species level. He suggests that the type specimen consists of intermediate lower and upper pitchers as opposed to true forms of either, making them appear atypical. nom.nud. [=N. stenophylla] • Nepenthes fusca subsp. kostermansiana J.H.Adam & Wilcock ex Jebb & Cheek (1997) It is deposited at the National Herbarium of the Netherlands in Leiden. This confusion stemmed from the likeness of N. fusca and N. maxima, and from apparently mislabelled seeds collected by Charles Curtis. Curtis was not meticulous in recording where he located individual plants; although it was originally believed that he collected N. curtisii (now considered synonymous with N. maxima) in Borneo, botanist Charles Clarke points out that he also visited Sulawesi on the same trip, and N. maxima is common there. The authors described the taxon as a Sabah endemic growing at elevations of 1,200 to 1,500 m. and in Pitcher Plants of Borneo by Anthea Phillipps, Anthony Lamb, and Ch'ien Lee, these features were considered to fall within the natural variability of N. fusca. The taxon was reinstated in 2019 based on isolated distributions and morphology, and the previous synonymy was attributed to the frequent hybridization between members of Nepenthes. Nepenthes dactylifera In his 1997 monograph, Nepenthes of Borneo, Charles Clarke lists the undescribed taxon "Nepenthes sp. A", which has been recorded from Gunung Mulu National Park in Sarawak. of N. faizaliana, In 2019, "Nepenthes sp. A" was included as a synonym of the novel taxon Nepenthes dactylifera. Notably, several ecological distinctions were drawn between N. dactylifera and N. fusca, such as epiphytic habit observed in N. dactylifera as opposed to the terrestrial habit of N. fusca. ==Description==

, Mount Kinabalu Nepenthes fusca is a climbing plant. The stem may attain a length of 10 m 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. Developing parts of the plant bear an indumentum of long, brown hairs. However, most of these disappear during the normal course of development, and mature parts only have a sparse covering of short, brown hairs. ==Ecology==

, and N. stenophylla'' growing in an exposed site along a logging road to Mount Murud in Sarawak Nepenthes fusca is endemic to Borneo, where its range stretches from Central Kalimantan to northwestern Sabah. and in Sarawak it has been found at only 300 m in hill forest. In this respect, it can be considered the "ecological equivalent" of N. bongso from Sumatra. More rarely, N. fusca grows terrestrially in exposed sites near montane forest and natural hybrids with all of these have been recorded. including Kambarangoh, the Marai Parai plateau, the mountain's East Ridge, and the Bambangan River at around 1,500 m. despite being frequently cut back as part of road maintenance. Nearby plants from more sheltered locations fared better and appeared to have recovered by the following year. Nepenthes fusca can be viewed along the road leading to the disused Mamut Copper Mine, adjacent to Mount Kinabalu. There it is sympatric with N. macrovulgaris, N. stenophylla, and the natural hybrid N. fusca × N. stenophylla; N. burbidgeae grows a short distance away. A lone plant growing on a ridge top at 1,962 m was found to have a small bush frog (probably Philautus aurantium) in one of its partly dried, 15 cm-long pitchers. Scattered plants have also been recorded from a rocky clearing at 1,592 m, growing alongside Gleichenia truncata ferns and bamboo orchids; these plants have rather unremarkable red-speckled but otherwise plain green pitchers, though unusually the stem and underside of the midrib are almost black. The species is abundant on Mount Alab, the highest peak of the Crocker Range, where a number of colour variants have been documented, including one with wholly green lower pitchers save for red mottling on the interior and underside of the lid. It is also an uncommon inhabitant of roadside embankments there. Plant poaching is of far lesser concern, as this species is not particularly sought after in the carnivorous plant hobby and its epiphytic habit makes it largely inaccessible to collectors. ==Related species==

Among the closest relatives of N. fusca are the Bornean species N. epiphytica, may also be closely allied. The lower pitchers of N. hurrelliana are distinctive, but the upper ones bear a close resemblance to those of N. fusca. Of the Bornean pitcher plant flora, only these two species have such a narrowly triangular lid. The upper pitchers of N. hurrelliana differ in having a horizontal mouth that rises abruptly into a long neck at the back and in having a hirsute basal crest on the underside of the lid. Nepenthes vogelii differs in having much smaller pitchers and lacking appendages on the underside of the lid. Nepenthes fusca is also thought to be closely related to Sulawesi's N. eymae, and N. maxima, which is widespread in Sulawesi, New Guinea, and the Maluku Islands. ==Natural hybrids==

Due its widespread distribution throughout Borneo, N. fusca forms natural hybrids with a relatively large number of other species. However, like N. fusca itself, these are often hard to find due to the species's epiphytic growth habit.) and N. lowii. However, in their 2008 book, Pitcher Plants of Borneo, Anthea Phillipps, Anthony Lamb and Ch'ien Lee pointed out that the plants exhibit influences of N. fusca, such as a triangular lid and an elongated neck. Nepenthes naquiyuddinii is generally thought to be a heterotypic synonym of N. reinwardtiana, N. rajah, ==Cultivation==

s, no test groups showed a survival rate of less than 75%. Nepenthes fusca was found to tolerate temperatures in the range of . A nighttime drop in temperature below was necessary for good growth; plants that were not exposed to such a drop grew poorly and produced fewer pitchers. The experiments suggested that N. fusca grows best when relative humidity is in the range of 65 to 90%. The species seemed to do best in growing media with a high proportion of organic matter (such as a mixture consisting of 10% peat moss chunks, 30% perlite, and 60% of any combination of Sphagnum moss and fir bark). Soil with a slightly acidic pH of 4.5 to 5.0 produced the best results. Optimal soil conductivity appeared to lie between 10 and 45 microsiemens. An illuminance of 6,400–8,600 lx (600–800 fc) proved to be optimal when plants were grown under sunlight, high pressure sodium, and metal halide lamps. However, specimens placed under an even combination of Gro-Lux and cool white fluorescent lamps at 5,400–7,500 lx (500–700 fc) exhibited the most vibrant colours (although growth rates remained the same). Plants moved from the former to the latter light set up showed a significant change in pigmentation; green leaf blades turned bronzy and speckles on the pitchers darkened markedly. Nepenthes fusca was found to respond well to a quarter-strength fertilizer that was applied to the pitchers. Ants were also an effective food source. ==Notes==