All species › Caryophyllales › Tropical pitcher plant family › Nepenthes appendiculata
Nepenthes appendiculata
A pitcher plant that received its name only in 2011, and owes it to a single organ: beneath the lid of the upper pitchers hangs a stalked, woody appendage several centimetres long, studded with a handful of huge nectar glands. Nepenthes appendiculata lives as an epiphyte in the cloud forest of the Hose Mountains in the heart of Sarawak, a remote massif reached late by botanists. Our own species list placed it on Sumatra; the description and the world checklist leave no doubt that it is a plant of Borneo.
No photograph of this species under a Creative Commons licence or in the public domain is in the guide yet.
Identification
A slender climber with cylindrical stems no more than about two metres long and six to nine millimetres thick, covered in short red-brown hairs. The leaves are almost stalkless, elliptic, to 14 cm long and 6 cm wide, with an acute tip; the tendril is 30 to 40 cm long and coiled in the middle. Lower pitchers are narrow, nearly cylindrical and slightly swollen below, to 10.5 cm tall and 3 cm wide, with two fringed wings, an obliquely set ovate mouth and a peristome to 8 mm wide with comb-like teeth; the small lid bears filiform appendages. Upper pitchers are much larger, to 24.5 cm tall and nearly 5 cm wide, wingless but with clear ridges down the front, and beneath their heart-shaped lid sits the characteristic stalked appendage of about 3.4 cm.
Similar species
The species belongs to the circle around Nepenthes fusca and the other narrow-pitchered cloud-forest species of Borneo, and the description compares it explicitly with that group. Nepenthes fusca has a narrow triangular lid with at most a low crest at its base; in N. appendiculata the upper-pitcher lid is broad and cordate, and the woody, stalked appendage with its nine to fifteen large glands is developed like this in no relative. Other Bornean species with a pronounced lid appendage, such as N. burbidgeae, have an entirely different, rounded pitcher and grow on the ground. A narrow upper pitcher without this appendage is therefore almost certainly another species.
The trap and how it works
A pitfall of the ordinary Nepenthes kind, but with a marked emphasis on the lure. The stalked appendage under the upper-pitcher lid hangs directly over the mouth, and its nine to fifteen greatly swollen nectar glands lie exactly where a visiting insect has to stand to reach them. An insect feeding there has its feet on or just above the peristome and easily drops into the pitcher. Nothing has been published on the prey of this species; the shape of the upper pitchers, long, narrow and hanging free in the moss, points to flying and climbing insects, as in its cloud-forest relatives. The small, winged lower pitchers are produced sparingly and catch mostly on the mossy ground.
Habitat and ecology
An epiphyte of upper montane cloud forest (B1), at 1450 to 1700 m. This is forest in which trunks, branches and floor lie under a thick layer of moss and liverworts, almost constantly in cloud or mist, with a low, stunted canopy. The plant roots in that moss on trunks and branches and climbs through the canopy with its tendrils; it stands in half shade to light, but never in open vegetation. The soil itself plays no part: nutrients come from the moss, from rain and from prey. The description tells us little more about the habitat than this.
Distribution and elevation
Endemic to Borneo, and there, as far as known, confined to the Hose Mountains in central Sarawak, Malaysia. The massif lies far from roads and villages, and the species may well grow on neighbouring summits without anyone having looked. The known altitudinal range is 1450 to 1700 m. Our own species list gave Sumatra as its area; that is wrong, since both the original description and the World Checklist (WCVP) give Borneo only.
- Recorded (one-degree cells)
Forms and variation
No varieties or forms have been described, and the material on which the species rests is limited: the 2011 description is based on a small number of plants from one range. As in almost all Nepenthes, lower and upper pitchers differ strongly, and here the difference is especially large: lower pitchers are under 11 cm tall and winged, upper ones more than twice that height, wingless and carrying the large appendage. No natural hybrids are mentioned in the literature consulted.
Where and when to see it
This is not a species for a day trip. The Hose Mountains can be reached only by an organised expedition by river and forest trail, with permission from the Sarawak authorities and with local guides. Anyone who gets there should look up in the cloud forest above 1450 m, at trunks and branches: the upper pitchers hang among the moss, and the dark, woody appendage under the lid is visible to the naked eye at close range. Binoculars help for pitchers higher in the canopy, without touching the plant.
Conservation status
The Red List assesses the species as Least Concern. That judgement rests mainly on the remoteness of the area: the cloud forest of the Hose Mountains lies above the zone that is logged and planted, and the plant grows where collectors can hardly reach it. At the same time it is known from a single range, so any change there affects the entire distribution at once. As a member of the genus it is listed in CITES Appendix II, so international trade in wild plants requires a permit.
Scientific name
Nepenthes appendiculata | Lee, Bourke, Rembold, Taylor & Yeo, 2011
Nepenthes appendiculata was described in 2011 by Ch'ien C. Lee, Greg Bourke, Thomas Rembold, William Taylor and Swee Tin Yeo, in Stewart McPherson's book New Nepenthes: Volume One. The species is restricted to the Hose Mountains of central Sarawak, Borneo, occurring at elevations between 1,450 and 1,700 m. The name refers to the enlarged glandular appendage on the lower surface of the lid, the species' most distinctive characteristic.
World Checklist of Vascular Plants (WCVP), via Plants of the World Online (POWO), Royal Botanic Gardens, Kew.