Nepenthes Bellii - Related Species

Related Species

Pitcher morphology of the two closest relatives of N. bellii: a lower pitcher of N. merrilliana (left) and an upper pitcher of N. surigaoensis (right)

The combination of subglobular lower pitchers, densely fringed wings (often with clustered filaments) and proportionately long tendrils separate N. bellii from all other species with the possible exception of the miniature N. argentii. However, the latter species can hardly be confused with N. bellii as it does not produce a climbing stem, differs markedly in the shape of the lamina, and has a uniquely curved peristome that continues along the lower surface of the lid.

Nepenthes bellii is closely allied to N. merrilliana and N. surigaoensis and shares with these species a similar morphology of the pitchers and laminae as well as a reddish colouration of the uppermost leaves. It is not easily confused with them, however, because it is much smaller in all respects, particularly in the size of its pitchers and inflorescence. More generally, N. bellii appears to fall under B. H. Danser's classical Insignes group, which also includes N. burkei, N. insignis, N. merrilliana, and N. ventricosa, among others, with N. sibuyanensis being a recent addition.

Nepenthes bellii was also compared to N. micramphora in the formal description of the latter, in which the authors noted that the stem, laminae and inflorescence of N. micramphora match those of N. bellii "almost exactly". Indeed, prior to the description of N. micramphora in 2009, the species was misidentified as N. bellii on its native Mount Hamiguitan. Nepenthes micramphora can be clearly distinguished by its distinct pitchers and even smaller vegetative features.

In their 2001 monograph, Martin Cheek and Matthew Jebb also noted a "remarkable resemblance" between the lower pitchers of N. tomoriana and those of N. bellii.