Nepenthes Benstonei - Related Species

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 endemic 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.