Nepenthes attenboroughii

Appearance

"Nepenthes attenboroughii" is a terrestrial upright or scrambling shrub. The stem, which may be up to 3.5 cm thick, is circular in cross section and attains a height of up to 1.5 m.

The species is characterised by its large and distinctive bell-shaped lower and upper pitchers and narrow, upright lid. The type specimen of "N. attenboroughii" was collected on the summit of Mount Victoria, an ultramafic mountain in central Palawan, the Philippines.

Naming

"Nepenthes attenboroughii" is closely related to the Palawan species, "N. deaniana", "N. leonardoi", "N. mantalingajanensis", "N. mira", and "N. palawanensis", to "N. peltata" from Mindanao, and to "N. rajah" from Borneo.

The stated relationship of this taxon with species from Borneo and Mindanao agrees with observations made in the description of "N. mira", and is further supported in the type description of "N. attenboroughii" by previously overlooked paleogeographical evidence. Based on this evidence, the authors reason that these species, predominantly found growing on ultramafic soils on Palawan and Mindanao, are likely to have arisen as a result of the radiative speciation of a common ancestor in Borneo.

Distribution

This species is endemic to the Victoria Massif in Palawan. There, it grows from 1450 m above sea level to the summit of Mount Victoria at 1726 m. Originally known only from Mount Victoria itself, it has since been found on the largest peak of the Victoria Massif, Mount Sagpaw, and along the connecting ridges from the site of first collection. The species is found among shrubs 0.8–1.8 m tall in relatively scattered populations of plants on rocky, ultramafic soil. It is not sympatric with other "Nepenthes" species and no natural hybrids have been recorded.

The summit flora of Mount Victoria includes "Leptospermum" sp., "Medinilla" spp., "Dracaena" sp., "Vaccinium" sp., various grasses, as well as the sundew "Drosera ultramafica", which grows at similar elevations to "N. attenboroughii".

Status

"Nepenthes attenboroughii" is assessed as Critically Endangered by the World Conservation Union on account of its restricted distribution and the threat posed by plant poachers.

Evolution

"Nepenthes attenboroughii" was discovered by Alastair Robinson, Stewart R. McPherson and Volker B. Heinrich in June 2007, during a 2 month research expedition to catalogue the different species of pitcher plant found across the Philippine Archipelago. The expedition was initiated after missionaries reported seeing giant "Nepenthes" on the mountain in 2000.

The formal description of "N. attenboroughii" was published in February 2009 in the "Botanical Journal of the Linnean Society". The herbarium specimen "A. Robinson" AR001 is the designated holotype, and is deposited at the herbarium of Palawan State University, Puerto Princesa City.

Further accounts of this species appeared in McPherson's "Pitcher Plants of the Old World", published in May 2009, and in the December 2009 issue of the "Carnivorous Plant Newsletter".