Nepenthes villosa

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Nepenthes villosa

Hanging pitcher of N. villosa. Mount Kinabalu, Borneo.

Conservation status

Vulnerable (IUCN)

Scientific classification

Kingdom:	Plantae
Division:	Magnoliophyta
Class:	Magnoliopsida
Order:	Caryophyllales
Family:	Nepenthaceae
Genus:	Nepenthes
Species:	N. villosa

Binomial name

Nepenthes villosa
Hook.f. (1852)

Distribution of N. villosa.

Nepenthes villosa (Latin: villosus = hairy) is a species of tropical pitcher plant belonging to the genus Nepenthes. It grows at higher elevations than any other Bornean Nepenthes species, at an altitude of 2400 to 3200 m. N. villosa is endemic to mossy and sub-alpine forest on Mount Kinabalu and neighbouring Mount Tambuyukon. N. villosa is characterised by its highly-developed and intricate peristome, which is also used to distinguish it from the closely related N. edwardsiana and N. macrophylla.^[1]

[edit] Taxonomy

N. villosa is most closely related to N. edwardsiana and N. macrophylla. There has been much taxonomic confusion surrounding the status of these three taxa.

Joseph Dalton Hooker noted the similarity between the first two species as follows:^[2]

This most remarkable plant [N. villosa] resembles that of edwardsiana in so many respects, especially in the size, form and disposition of the distant lamellae of the mouth, that I am inclined to suspect that it may be produced by young plants of that species, before it arrives at a stage when the pitchers have elongated necks.

B. H. Danser, in his 1928 monograph The Nepenthaceae of the Netherlands Indies, wrote the following concerning the taxonomy of N. villosa:^[3]

With some hesitation I unite N. villosa and N. Edwardsiana under the first name. Hooker himself already suggested the nessecity of this union and Beck was the first to realise it in nomenclatorial sense. Hooker supposed N. Edwardsiana to be a more developed form of N. villosa, but I think the relation between the two forms is another, N. Edwardsiana being the normal form, i.e. more agreeing with the normal type of most Nepenthes species, N. villosa being the form of high mountains, flowering in the juvenile stage of development. This is pointed out by the following facts. The form, originally described as N. villosa, has been found at a elevation of 2400 to 2700 m, N. Edwardsiana, however, at an elevation of 1500 to 1650 m. N. Edwardsiana is described as a climbing plant, N. villosa as low-climbing or prostrate. The indumentum of N. villosa is more dense than that of N. Edwardsiana, but already Hooker drew attention to the fact, that this is a difference only of degree. The difference in the shape of the pitchers also occurs in similar forms of other species, the differences in the inflorescences too. Yet there may remain minor differences, that can not be ascribed to the differences in habitat. Macfarlane says: "Examinatione microscopica probatur, illas species distinctas esse". This probably is based on the old belief that plants, which differ anatomically, can not be forms of the same species. The plant Burbidge describes as N. Harryana and which may be a hybrid of N. Edwardsiana and N. villosa, can as well be an intermediate form. To argue his opinion, Burbidge says: "they are quite distinct in zone of the mountain", but this exactly is an argument for the supposition, that all three Nepenthes mentioned are forms of a single species, originated under the influence of the different elevation of the habitat. Considered in this way N. villosa, though only found on Mt. Kinabalu, seems to be rather variable, but the variability is very insufficiently investigated. About the mode of growth Burbidge remarks (l.c.) that N. Edwardsiana is purely epiphytical on Casuarinas, Dacrydiums, Rhododendrons &c." Whereas N. villosa according to the same author is "different in terrestrial habit". Of course it is questionable, whether this is always so, but in general this may be the case when the relation between the two forms, described as N. villosa and N. Edwardsiana, is as I suppose.

[edit] Natural hybrids

Two natural hybrids involving N. villosa have been recorded:^[1]

N. edwardsiana × N. villosa [=N. × harryana]
N. rajah × N. villosa [=N. × kinabaluensis]

N. × kinabaluensis

[edit] References

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Nepenthes villosa

^ ^a ^b Clarke, C.M. 1997. Nepenthes of Borneo. Natural History Publications (Borneo), Kota Kinabalu.
^ Phillipps, A. & A. Lamb 1996. Pitcher Plants of Borneo. Natural History Publications (Borneo), Kota Kinabalu.
^ Danser, B.H. 1928. The Nepenthaceae of the Netherlands Indies. Bulletin de Jardin de Botanique, Buitenzorg, Série III, 9(3-4): 249-438.

Clarke et al. (2000). Nepenthes villosa. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 11 May 2006. Listed as Vulnerable (VU D2 v2.3).