Nepenthes villosa

Nepenthes villosa was formally described in 1852 by Joseph Dalton Hooker. The description was published in Icones plantarum and accompanied by an illustration. The species was first collected in 1858 by Hugh Low when he made his second ascent of Mount Kinabalu together with Spenser St. John. That year, N. villosa was also covered in ''Flore des Serres et des Jardins de l'Europe'' by Louis van Houtte, in which the same illustration was reproduced along with the incorrect identification. In 1859, N. villosa was again described and illustrated in J. D. Hooker's treatment of the genus published in The Transactions of the Linnean Society of London. The illustration and description were reproduced in Spenser St. John's Life in the Forests of the Far East, published in 1862. B. H. Danser treated N. edwardsiana in synonymy with N. villosa in his seminal monograph "The Nepenthaceae of the Netherlands Indies", published in 1928. The work included a revised Latin diagnosis and botanical description of N. villosa. Danser listed four herbarium specimens that he identified as belonging to N. villosa. These include two collected by George Darby Haviland from Mount Kinabalu in 1892. One of these, Haviland 1656/1232, was collected at an elevation of . It includes male floral material and is deposited at the Herbarium of the Sarawak Museum. The second specimen, Haviland 1813/1353, was collected from the Marai Parai plateau at an elevation of ; it likely represents N. edwardsiana. It is also deposited at the Herbarium of the Sarawak Museum. It does not include floral material. G. D. Haviland explored the Mount Kinabalu area with his brother H. A. Haviland between March and April, 1892, and must have collected these specimens during this time. Additionally, Danser lists two specimens collected by Joseph Clemens in 1915. The first, Clemens 10627, was collected on November 13 from Paka Cave to Low's Peak. It includes female floral material. The second, Clemens 10871, was collected at Marai Parai between November 22 and November 23, and does not include floral material. Both specimens are deposited at the Bogor Botanical Gardens (formerly the Herbarium of the Buitenzorg Botanic Gardens) in Java. In cultivation In 2004, professional horticulturist Robert Sacilotto published a summary of measured tolerances of six highland Nepenthes species, including N. villosa, based on experiments conducted between 1996 and 2001. Many of the N. villosa plants in cultivation today originate from a particularly vigorous tissue culture clone introduced by Phill Mann of Australia and later sold by the Sri Lankan-based plant nursery, Borneo Exotics. ==Description==

Nepenthes villosa is a weak climber, rarely exceeding in height, An unbranched spur, ≤ long, is inserted at the base of the lid. A study of 490 pollen samples taken from two herbarium specimens (J.H.Adam 1124 and J.H.Adam 1190, collected at an elevation of ) found the mean pollen diameter to be 37.2 μm (SE = 0.2; CV = 6.7%). The species has a dense indumentum of long, brown hairs that covers all parts of the plant. ==Ecology==

Nepenthes villosa is endemic to the upper slopes of Mount Kinabalu and neighbouring Mount Tambuyukon in Sabah, Borneo. the highest elevation of all Bornean Nepenthes species; only N. lamii from New Guinea is found at greater elevations. On Mount Kinabalu, N. villosa is common along the Mesilau Trail (between Pondok Magnolia and the meeting point with the old summit trail) and almost all the way up to the Laban Rata rest house; a particularly large population has been reported at around 3047 m. On Mount Tambuyukon, an altitudinal inversion has been noted, whereby N. villosa is more common at much lower elevations of 1600–1900 m, being replaced by N. rajah towards the summit. Nepenthes villosa often grows in mossy forest and sub-alpine forest dominated by species of the genera Dacrydium and Leptospermum, particularly Leptospermum recurvum. It has also been recorded growing among shrubs, grass, and boulders in open areas. Here the soil may become relatively dry, although relative humidity is usually close to 100% as the slopes are often enveloped in clouds. Like many Nepenthes from the Mount Kinabalu area, it is endemic to ultramafic soils. Although many plants grow along Mount Kinabalu's summit trail and are easily accessible to climbers, all known populations of the species grow within Kinabalu National Park and so their collection is illegal. In 1997, Charles Clarke suggested a revised assessment of Conservation Dependent based on this. Clarke writes that N. villosa "has a secure future", although he adds that climbers have had a significant impact on populations of the species growing along the summit trail, with the number of plants having declined in recent years. A 2002 study found 1,180 individual N. villosa growing in 11 plots, each measuring 0.01 hectares, at elevations of between and on Mount Kinabalu. This number constituted 94% of the pitcher plants recorded from the plots, the rest being N. × kinabaluensis. ==Related species==

Nepenthes 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, who described both N. edwardsiana and N. villosa, noted the similarity between the two species as follows: In his 1908 monograph, John Muirhead Macfarlane wrote the following with regards to the two species: "Examinatione microscopica probatur, illas species distinctas esse". This is probably "based on the old belief that plants, which differ anatomically, can not be forms of the same species". It was later elevated to species status by Matthew Jebb and Martin Cheek. This interpretation was supported by Charles Clarke, who noted that N. edwardsiana and N. villosa "have more in common" than N. edwardsiana and N. macrophylla. N. villosa also shows affinities to N. peltata of Mindanao. ==Natural Hybrids==

Two natural hybrids involving N. villosa have been recorded. John Muirhead Macfarlane was the first to realise its hybrid origin and described it as such in his monograph of 1908. It was finally described in 1976 by Shigeo Kurata as N. × kinabaluensis. The name was published in Nepenthes of Mount Kinabalu, but it is a nomen nudum, as it had an inadequate description and lacked information on the type specimen. The name was subsequently republished by Kurata in 1984 and by J. H. Adam and C. C. Wilcock in 1998. The pitchers of N. × kinabaluensis may be quite large, but do not compare to those of N. rajah or N. × alisaputrana (N. burbidgeae × N. rajah). N. × kinabaluensis can only be found on Mount Kinabalu (hence the name) and nearby Mount Tambuyukon, where the two parent species occur sympatrically. The only accessible location from which this hybrid is known is the Kinabalu summit trail, between Layang-Layang and the helipad, where it grows at about in a clearing dominated by Dacrydium gibbsiae and Leptospermum recurvum trees. N. × kinabaluensis has an altitudinal distribution of to . It grows in open areas in cloud forest. The hybrid is generally intermediate in appearance between its parent species. Raised ribs line the inner edge of the peristome and end with elongated teeth. These are more prominent than those found in N. rajah and smaller than those of N. villosa. The peristome is coarse and expanded at the margin (but not scalloped like that of N. rajah), the lid orbiculate or reniform and almost flat. In general, pitchers are larger than those of N. villosa and the tendril joins the apex about below the leaf tip, a feature which is characteristic of N. rajah. In older plants, the tendril can be almost woody. N. × kinabaluensis is an indumentum of villous hairs covering the pitchers and leaf margins, which is approximately intermediate between the parents. Lower pitchers have two fringed wings, whereas the upper pitchers usually lack these. The colour of the pitcher varies from yellow to scarlet. N. × kinabaluensis seems to produce upper pitchers more readily than either of its parents. In all respects N. × kinabaluensis is intermediate between the two parent species and it is easy to distinguish from all other Nepenthes of Borneo. However, it has been confused once before, when the hybrid was misidentified as both N. rajah and N. villosa in Letts Guide to Carnivorous Plants of the World, published in 1992. ==Notes==