Nepenthes Rajah - Natural Hybrids

Natural Hybrids

Nepenthes rajah is known to hybridise with several other species with which it is sympatric. It seems to flower at any time of year and for this reason it hybridises relatively easily. Charles Clarke also notes that "N. rajah, more than any other species, appears to have been successful in having its pollen transported over considerable distances. Consequently, a number of putative N. rajah hybrids exist without the parent plant growing nearby". However, it appears that the limit as to how far pollen can be transported is approximately 10 km. Hybrids between N. rajah and all other Nepenthes species on Mount Kinabalu have been recorded. Due to the slow-growing nature of N. rajah, few hybrids involving it have been artificially produced yet.

At present, the following natural hybrids are known:

• N. burbidgeae × N. rajah
• N. edwardsiana × N. rajah
• N. fusca × N. rajah
• N. lowii × N. rajah
• N. macrovulgaris × N. rajah
• N. rajah × N. stenophylla
• N. rajah × N. tentaculata
• N. rajah × N. villosa

The "Mountain Garden" of Kinabalu National Park contains a number of well-grown Nepenthes, including the rare hybrid N. rajah × N. stenophylla. This plant has leaves resembling those of N. stenophylla, but the lid and wings are typical of N. rajah. The peristome is strongly influenced by N. stenophylla and bristles are present at the border of the lid, a unique characteristic of this hybrid. It occurs at an altitude of 1500–2600 m.

A single example of N. lowii × N. rajah grows along the Mesilau nature trail.

Two hybrids of N. rajah have been formally described and given specific names: N. × alisaputrana and N. × kinabaluensis. Both are listed on CITES Appendix II and the latter is also considered Endangered (EN (D)) under current IUCN criteria.