splendid pitcher-plant

Nepenthes edwardsiana is a climbing plant. The stem can attain a length of 15 m and is up to 10 mm in diameter. Internodes are up to 35 cm long and circular in cross section.

Leaves are coriaceous and petiolate. The lamina is truly lanceolate in shape and may be up to 30 cm long by 7 cm wide. It has an acute-obtuse apex that is occasionally acuminate. The base of the lamina is gradually or abruptly contracted at the petiole. The petiole is canaliculate and up to 15 cm long. It is generally winged and bears a partly amplexicaul sheath that clasps the stem for two-thirds to three-quarters of its circumference. One to three longitudinal veins are present on either side of the midrib. Pinnate veins are indistinct. Tendrils are generally between one and two times as long as the lamina and grow to 35 cm in length.

The pitcher base is bulbous to ovoid, with the pitcher cup becoming cylindrical in the upper two-thirds to three-quarters. The pitchers are some of the largest in the genus, sometimes exceeding 50 cm in height and 15 cm in width, although they are usually around 30 cm high. Wings at the front of the pitcher cup are either greatly reduced or absent altogether. On the inner surface of the pitcher, the glandular region is present in the bulbous portion. The mouth is elongated into a neck and has an oblique insertion. The peristome is cylindrical and up to 30 mm wide. …

Nepenthes edwardsiana is endemic to the highland slopes of Mount Kinabalu and the eastern side of neighbouring Mount Tambuyukon in Sabah, Borneo. On Mount Kinabalu, this species has been recorded from the Marai Parai plateau, East Ridge, Upper Kolopis River, and an area below the Kambarangoh Telekom station (below Pondok Lowii). Nepenthes edwardsiana has an altitudinal distribution of 1,500–2,700 m above sea level. Anthea Phillipps and Anthony Lamb note that plants growing in the Racemobambos bamboo forest on Mount Tambuyukon produce some of the longest and finest pitchers, having a pronounced waist and ranging in colour from pink to reddish-orange. On the Marai Parai plateau of Mount Kinabalu, N. edwardsiana grows amongst shrubs up to 5 m high. Pitchers on these plants rarely exceed 30 cm. The species does not grow along the Kinabalu summit trail and so very few visitors to the park manage to see it. A specimen is kept at the "Mountain Garden" near Kinabalu Park Headquarters. During the last ice age, around 20,000 to 10,000 years ago, Mount Kinabalu had an ice cap on its summit. As such, it appears that N. edwardsiana is a relatively recent species in evolutionary terms. Contrary to the observations of Frederick William Burbidge, N. edwardsiana grows not only as an epiphyte, but also occurs terrestrially on moss-covered rocks. …

Nepenthes edwardsiana is very rare in cultivation and little information has been published on its growing requirements. Generally speaking, it is an alpine plant that requires highland conditions to grow well. In 2004, professional horticulturist Robert Sacilotto wrote a summary of measured tolerances of highland Nepenthes species, based on experiments conducted between 1996 and 2001. Out of all of the studied species, N. edwardsiana proved to be the most challenging. Cotyledon-stage seedlings showed a 100% mortality rate when exposed to the following conditions: relative humidity constantly over 90%, water droplets present on the leaves, soil conductivity over 45 microsiemens, and soil pH above 6. However, several plants grew well in a substrate consisting of 50% perlite, 30% Sphagnum moss, 10% peat moss chunks, and 10% fir bark. A top dressing of live Sphagnum was found to provide a good anchoring point for developing roots. Humidity levels of 65 to 85% appeared to be optimal, although more mature plants over 1 year old were able to tolerate exposure to relative humidity in the range of 90 to 99% for up to three days. The highest growth rate was exhibited by plants that experienced warm days, with temperatures of 21 to 29 °C (70 to 84 °F), and cool nights, with temperatures of 13 to 16 °C (55 to 61 °F). …

The type specimen of N. edwardsiana was collected on Mount Kinabalu in 1858 by Hugh Low and Spenser St. John. Designated as Low s.n., the specimen is deposited at the Royal Botanic Gardens, Kew. Nepenthes edwardsiana was formally described[note a] in 1859 by Joseph Dalton Hooker. Hooker named the species after George Edwardes, Governor of the Crown Colony of Labuan, at the request of his friend Hugh Low.[note b] Hooker's original description and illustration were reproduced in Spenser St. John's Life in the Forests of the Far East, published in 1862. St. John wrote the following account of N. edwardsiana on Mount Kinabalu:

As we ascended, we left the brushwood and entered a tangled jungle, in which few of the trees were large. The spur of the mountain became very narrow, sometimes not much wider than the path, and was greatly encumbered at one part by the twining stems of the Nepenthes Edwardsiana. This handsome plant was not, however, much diffused along the spur, but confined to a space about a quarter of a mile in length, and climbed upon the trees around, with its fine pitchers hanging from all the lower boughs. We measured one plant and it was twenty feet in length, quite smooth, and the leaves of a very acute shape at both ends. …