Splendid Pitcher Plant

Nepenthes edwardsiana is a highland pitcher plant endemic to Mount Kinabalu and Mount Tambuyukon in Sabah, Malaysian Borneo. It is considered one of the most spectacular species, with some of the largest pitchers in the genus and the most highly developed peristome ribs of any.

Nepenthes edwardsiana is a climbing plant with a stem up to 15 m long. Its leaves are lanceolate, up to 30 cm long, on a winged leaf stalk up to 15 cm long, and the tendrils reach 35 cm.

The pitchers are bulbous at the base and cylindrical in the upper two-thirds to three-quarters. They are usually around 30 cm (12 in) tall but can exceed 50 cm (20 in), and are among the largest in the genus. The mouth rises into a neck, and the cylindrical peristome, up to 30 mm wide, carries very highly developed ribs and teeth. Pitchers range from light yellow to dark red outside and are usually white inside. Most of the pitcher is flexible, peristome ribs included; only the base, where digestion takes place, is rigid.

The plant has only an inconspicuous covering of very short hairs. It is most closely related to N. villosa and N. macrophylla. It differs from N. villosa in its elongated pitchers, usually acute leaf tip, near-hairless surface and bractless flower stalks, and the two grow at different altitudes. Their natural hybrid is N. × harryana.

Төрөлх бүс нутаг: Mount Kinabalu and Mount Tambuyukon, Sabah, Borneo (endemic)

Уур амьсгалын бүсүүд: Tropical highland (1,500-2,700 m)

Nepenthes edwardsiana grows on the highland slopes of Mount Kinabalu and the eastern side of Mount Tambuyukon at 1,500 to 2,700 m. It typically grows among ridge-top vegetation in dense mossy forest, both as an epiphyte and on moss-covered rocks, mostly on ultramafic soils. Its habitat is constantly moist, as the slopes are often wrapped in cloud. The finest pitchers grow in the Racemobambos bamboo forest of Mount Tambuyukon. It does not grow along the Kinabalu summit trail, so few visitors see it.

Насанд хүрсэн хэмжээ: Stem to 15 m; pitchers usually about 30 cm (12 in), sometimes over 50 cm

Өсөлтийн хурд: Slow

Хавхын төрөл: Pitfall Trap

The pitchers are pitfall traps with the digestive glands in the bulbous base. In N. edwardsiana each flattened peristome tooth carries a narrow-mouthed gland on its outer face, and below each tooth there is a distinct elliptic pocket, a structure that separates it from N. villosa.

Spenser St John measured a pitcher 21.5 inches (about 55 cm) long on Mount Kinabalu in 1858.
Alfred Russel Wallace mentioned it in The Malay Archipelago (1869).
Mount Kinabalu had an ice cap during the last ice age, so the species is thought to be relatively recent.
The 1997 to 1998 El Niño drought and fires severely depleted wild populations on Kinabalu.
In seedling trials it was the most fragile of the highland species tested.
The IUCN Red List lists it as Vulnerable, from a 2000 assessment (Schnell et al., assessment T40107A10314266); Charles Clarke has argued that, as all known populations are inside protected areas, it is unlikely to become threatened.

Hugh Low and Spenser St John collected the type on Mount Kinabalu in 1858, and Joseph Dalton Hooker described the species in 1859, naming it at Low's request after George Edwardes, Governor of Labuan. St John described the plant climbing over the trees along a narrow spur, its brick-red pitchers hanging from the lower branches.

Its status has changed several times. Günther Beck treated it as a form of N. villosa in 1895; Macfarlane restored it as a species in 1908; Danser united the two again in 1928; and Hermann Harms separated them once more in 1936, a view supported by Shigeo Kurata in 1976 and unchallenged since. A similar plant from Mount Trusmadi, described in 1987 as a subspecies, was raised to species rank as N. macrophylla by Jebb and Cheek in 1997.

It is very rare in cultivation. Robert Sacilotto's seedling experiments, published in 2004, found it the most challenging of the highland species he grew.

1. Nepenthes edwardsiana, Wikipedia
2. Nepenthes edwardsiana, Caryophyllales Network: Nepenthaceae (after Cheek & Jebb 2001, Flora Malesiana I, 15)
3. Nepenthes: species of Borneo, The Carnivorous Plant FAQ (Barry Rice)
4. Experiments with highland Nepenthes seedlings: a summary of measured tolerances (Robert Sacilotto), Carnivorous Plant Newsletter 33(1): 26-31 (2004)
5. Nepenthes: basic cultivation, The Carnivorous Plant FAQ (Barry Rice)
6. Thumbnail guidelines on growing a tropical pitcher plant, The Carnivorous Plant FAQ (Barry Rice)