Nepenthes hurrelliana and N. murudensis are of putative hybrid origin, but are considered species by most taxonomists, as they form stable, fertile populations independent of their original parent species. The same could be said for stable hybrids such as N × kinabaluensis. Indeed, species status has been proposed for this taxon in the past.
Nepenthes natural hybrids recorded from the Philippines. The N. alata hybrids listed below involve N. alata in the broad sense ; this polymorphic taxon has recently been split into a large number of daughter species that now form the so-called "N. alata group".
N. alata × N. burkei
N. alata × N. merrilliana
? × N. mirabilis
N. alata × N. mindanaoensis
N. alata × N. mirabilis
? N. alata × N. petiolata
N. alata × N. pulchra
N. alata × N. truncata
N. alata × N. ventricosa
? N. pantaronensis × N. sumagaya
N. bellii × N. merrilliana
N. bellii × N. mindanaoensis
N. ceciliae × N. pulchra
N. merrilliana× N. mindanaoensis
N. merrilliana × N. mirabilis
N. mindanaoensis × N. truncata
N. mindanaoensis × N. erucoides
N. palawanensis × N. aff. philippinensis
? N. petiolata × N. truncata
In addition, certain plants from Mount Hamiguitan are likely to represent crosses involving N. hamiguitanensis, N. justinae, N. micramphora, and N. peltata. Endemic species with no known natural hybrids:
N. abalata
N. abgracilis
N. aenigma
N. alzapan
N. argentii
N. armin
N. attenboroughii
N. barcelonae
N. cid
N. copelandii
N. cornuta
N. deaniana
N. extincta
N. gantungensis
N. graciliflora
N. halmahera
N. kitanglad
N. leonardoi
N. leyte
N. mantalingajanensis
N. mira
N. negros
N. philippinensis
N. ramos
N. robcantleyi
N. samar
N. saranganiensis
N. sibuyanensis
N. surigaoensis
N. talaandig
N. tboli
N. ultra
N. viridis
N. weda
N. zygon
N. sp. AnipahanNepenthes petiolata may itself have evolved from a cross between N. alata and N. truncata. It has been suggested that N. extincta might represent a natural hybrid between N. merrilliana and N. mindanaoensis, as both of these species grow near the type locality of N. extincta and share many morphological features with it. Plants from Mount Hamiguitan that were originally thought to represent the natural hybrid N. micramphora × N. peltata are now recognised as belonging to a distinct species of possible hybridogenic origin, N. hamiguitanensis''.
Nepenthes natural hybrids recorded from Peninsular Malaysia and Singapore.
N. albomarginata × N. ampullaria *
N. albomarginata × N. gracilis
? N. albomarginata × N. sanguinea
N. ampullaria × N. gracilis *
N. ampullaria × N. mirabilis *
N. ampullaria × N. rafflesiana *
N. benstonei × N. mirabilis
N. gracilis × N. mirabilis *
N. macfarlanei × N. ramispina
N. macfarlanei × N. sanguinea
N. mirabilis × N. rafflesiana *
N. ramispina × N. sanguinea
Two natural hybrids have been recorded from Singapore: N. × hookeriana and N. × trichocarpa. As such, all three species from Singapore are known to hybridise.
Nepenthes natural hybrids recorded from Indochina. For the purpose of this list, the area encompasses Cambodia, Laos, Myanmar, Thailand, and Vietnam.
N. ampullaria × N. gracilis *
N. ampullaria × N. mirabilis *
N. andamana × N. mirabilis
N. bokorensis × N. kampotiana
N. gracilis × N. mirabilis *
N. kampotiana × N. mirabilis
N. kongkandana × N. mirabilis
N. mirabilis × N. smilesii
N. mirabilis × N. thorelii
In addition, infraspecific hybrids between N. mirabilis var. globosa and N. mirabilis var. mirabilis are known to occur. Endemic species with no known natural hybrids:
Nepenthes natural hybrids recorded from Australia.
N. mirabilis × N. rowaniae
N. mirabilis × N. tenax
N. rowaniae × N. tenax
Complex hybrids involving all three species are also common. All three species from Australia are known to hybridise.
Outlying areas
There are six additional species endemic to areas other than those listed above. These are:
N. distillatoria
N. khasiana
N. madagascariensis
N. masoalensis
N. pervillei
N. vieillardii
Of these, the only species that could conceivably hybridise in the wild are N. madagascariensis and N. masoalensis. Although the ranges of the two species used to meet near Cape Masoala, no natural hybrids have ever been recorded.