"Nepenthes × alisaputrana" and "N. × kinabaluensis" are often fertile and thus may breed among themselves. Clive A. Stace writes that we may speak of "stabilised hybrids when they have developed a distributional, morphological or genetic set of characters which is no longer strictly related to that of its parents, ... if the hybrid has become an independent, recognisable, self-producing unit, it is "de facto" a separate species". "Nepenthes hurrelliana" and "N. murudensis" are two examples of species that have a putative hybrid origin. "Nepenthes × alisaputrana" and "N. × kinabaluensis" are sufficiently stabilised that a species status has been discussed. Indeed, "N. kinabaluensis" was described as a species by Adam & Wilcock in 1996.