Nepenthes benstonei

In their 1997 monograph, "A skeletal revision of Nepenthes (Nepenthaceae)", Matthew Jebb and Martin Cheek tentatively referred specimens collected from Bukit Bakar, near Macang, Kelantan, to N. sanguinea. The holotype of N. benstonei, Clarke s.n., was collected by Charles Clarke on 24 July 1998, on Bukit Bakar in Kelantan at an altitude of between 450 and 550 m. It is deposited at the Forest Research Institute of Malaysia in Kepong (KEP). Isotypes are held at Herbarium Bogoriense (BO), the Royal Botanic Gardens, Kew (K), the National Herbarium of the Netherlands in Leiden (L), the Forest Department in Sandakan (SAN), and the Singapore Botanic Gardens (SING). Furthermore, the shape of the lamina is unlike that of N. gracillima or N. ramispina; despite being narrow and lanceolate, it is proportionately considerably longer and has a much narrower, almost sub-petiolate base. Kiew partly attributed the narrower leaf bases of Ridley 16097 to a preservation artefact, but Clarke stated that this explanation could not fully account for the differences. He also noted that the specimen exhibits a decurrent leaf attachment. Taking all of these morphological features into account, Clarke felt that Ridley 16097 most likely represented a specimen of N. benstonei. At the time, he believed that Kiew had grouped both N. benstonei and N. ramispina with N. gracillima. But in a 2012 revision of the Nepenthes of Mount Tahan, which included a reappraisal of the taxonomically confused N. alba and N. gracillima, Clarke and Ch'ien Lee concluded that Kiew's concept of N. gracillima had encompassed N. alba, N. benstonei, and N. gracillima. Specimens from peninsular Thailand originally assigned to N. benstonei in Cheek and Jebb's 2001 monograph, "Nepenthaceae", have since been identified as belonging to a new species, N. thai. ==Description==

Nepenthes benstonei is a climbing plant. The stem, which may be branched, can attain a length of 10 m It is seen even more frequently in N. philippinensis. The stem and lamina have a sparse indumentum of simple white hairs. Short, branched reddish-brown hairs line the margins of the lamina. The outer surfaces of the pitchers bear a sparse covering of short, branched red hairs. The same hairs are more densely present on the margins of the lid and upper part of the pitcher directly below the peristome. Immature inflorescences have an indumentum of short white and red hairs throughout. The stem and leaves of N. benstonei bear a thick, waxy cuticle that often gives a whitish-blue sheen to the lamina and pitchers. Inflorescences are distinctly waxy throughout. No infraspecific taxa of N. benstonei have been described. ==Ecology==

Nepenthes benstonei is endemic to Peninsular Malaysia. It is known with certainty only from the summits of low hills in Kelantan and northern Terengganu, and from Mount Tahan in Taman Negara, Pahang. The species has a relatively wide altitudinal range of 150 to 1350 m above sea level. Nepenthes benstonei grows terrestrially among open, secondary vegetation, where it is exposed to direct sunlight. It is very abundant near the summit of Bukit Bakar, where it grows on cuttings beside a paved road leading to a Telekom Malaysia station at the summit. There, its altitudinal distribution appears to be restricted to 450–600 m. The species is also present on Mount Tahan, which at 2187 m is the highest mountain in Peninsular Malaysia. Its altitudinal range on Mount Tahan is known to extend from 800 to 1350 m. It is common on the mountain's lower slopes and can be seen along the western summit route from Sungai Relau, particularly on the tops of steep ridges at around 800–1200 m. It has been recorded growing along the western trail itself and from other disturbed sites, including areas affected by landslides. Plants have also been observed in dense forest, but these bear comparatively few pitchers. Though there were no confirmed reports of N. benstonei from Mount Tahan prior to 2012, the species's presence there is attested by much older herbarium material. Although the extent of its range is uncertain, N. benstonei appears to have a secure future in the wild as the type locality lies within a protected area and the species's unremarkable appearance means over-collection does not pose a serious threat. ==Related species==

In his description of N. benstonei, Charles Clarke noted two characteristics that he considered unique among Nepenthes. These were the production of multiple inflorescences and the presence of a thick, waxy cuticle on the leaves. Subsequent field studies have shown that the former is not unique to N. benstonei, but also occasionally occurs in other Nepenthes. Likewise, a number of other species, such as N. hirsuta from Borneo, are known to produce a waxy cuticle, although it is less developed than in N. benstonei. Otherwise, N. benstonei lacks remarkable characteristics and is distinguished from related species on the basis of its stem, leaves, peristome, lid, indumentum, and glands of the digestive zone. Nepenthes benstonei appears to be related to N. sanguinea, which is also native to Peninsular Malaysia. It can be distinguished on the basis of its significantly larger leaves, which are often sub-petiolate and differ in shape. Nepenthes benstonei also has longer tendrils and a denser indumentum. The presence of teeth on the peristome of lower pitchers and of a thick, waxy cuticle on the leaves also serve to distinguish these taxa. In addition, herbarium specimens of N. benstonei tend to dry to a lighter colour than those of N. sanguinea. The pitchers of N. benstonei also resemble those of N. smilesii from Indochina. Clarke suggests that N. benstonei may represent an evolutionary link between the Nepenthes taxa of Indochina and Peninsular Malaysia. Nepenthes benstonei also superficially resembles N. macrovulgaris from Borneo. It differs in producing multiple inflorescences, which are longer than those of N. macrovulgaris and bear one- or two-flowered partial peduncles, as opposed to exclusively two-flowered in the latter. The waxy coating of its leaves also separates these species. Nepenthes benstonei has also been compared to N. albomarginata, although the presence of a white band below the peristome, which gives the latter its name, makes identification easy. Upper pitchers of N. benstonei could be confused with those of N. mirabilis, although all other parts of the plant have little in common. In 2001, Charles Clarke performed a cladistic analysis of the Nepenthes species of Sumatra and Peninsular Malaysia using 70 morphological characteristics of each taxon. The resultant cladogram placed N. benstonei in an unresolved polytomy at the base of the Montanae/Nobiles clade, together with N. rhombicaulis. ==Natural hybrids==

N. benstonei does not commonly hybridize, and until 2025, only one natural hybrid involving N. benstonei was known. A single example of N. benstonei × N. mirabilis was discovered by Andrew Hurrell at the foot of Bukit Bakar, where the two species occur sympatrically. ==Notes==