Pitcher plant  (Nepenthes ephippiata)

This spectacular carnivorous plant belongs to the impressive family of tropical Asian pitcher plants (Nepenthes species). Nepenthes ephippiata is a vine, which climbs to a height of about six metres, and has modified pitcher-shaped leaves, which hang from coiled tendrils (4). The green and red cylindrical pitchers of Nepenthes ephippiata are very distinctive,with flattened leaf bases (2) (5). The pitchers contain an acidic fluid, secreted by the many glands which cover the inside surface of the pitcher, into which insects and other invertebrates fall (2). Nepenthes species usually have a ridge of hardened tissue lining the mouth of the pitcher, the peristome, bearing downward pointing teeth, also preventing insects from escaping. However, the peristome is very poorly developed in Nepenthes ephippiata (2). A lid overhangs the mouth of the pitcher with many bristles on the underside, which prevents rain water from diluting the pitcher fluid (2).

Endemic to central Kalimantan in the mountains of the Indonesian region of Borneo, at altitudes between 1,000 and 1,900 metres (5).

Nepenthes ephippiata grows amongst ridge top vegetation in mossy montane forest (2).

Pitcher plants are dioecious, meaning that male and female flowers grow on separate plants (4), and only begin to flower once the upper pitchers are produced (5). The flowers produce large amounts of nectar during the early evening and night, which evaporates by morning. This nectar attracts flies during the early evening and moths at night to aid pollination. Once fertilised, a fruit usually takes about three months to develop and ripen. The fruits of Nepenthes species produce between 100 and 500 very light, winged seeds, which can measure up to 30 millimetres long, and are thought to be dispersed by the wind (2) (6). Despite enormous numbers of seeds being produced, only a few manage to germinate and only a fraction of those survive to maturity (2).

Carnivorous pitcher plants are adapted to grow in soils low in nutrients. Although the plants do gain some nutrition through the soil, and energy through photosynthesis, they supplement this with a diet of invertebrates, usually consisting of ants, cockroaches, centipedes, flies and beetles (4). Insects are attracted to the pitchers by their bright colours and nectar, which is secreted by glands situated on the lid and the peristome of the pitcher. The insects fall into the acidic fluid at the base of the pitcher and are unable to escape. Digestive enzymes are then released to break down the drowned prey (4).

Despite the hostile environment of the pitchers, they can be home to number of animals. The red crab spider (Misumenops nepenthicola) inhabits pitcher plants in Malaysia, Indonesia and Singapore. This spider ambushes insects that crawl into the pitcher and preys upon other insects, such as mosquitoes, as they emerge from larvae that live in the pitcher fluid (2).

Nepenthes species are threatened by a combination of over-collection and habitat loss (2). The biodiversity of Indonesia is significantly threatened by widespread habitat destruction, caused by illegal and commercial logging and large agricultural projects such as rubber and oil palm plantations (7).

Nepenthes ephippiata is, at present, relatively widespread and listed under Appendix II of the Convention on International Trade in Endangered Species (CITES) which limits the international export of this species (3). However, trade is very difficult to regulate and there is no requirement for internationally traded Nepenthes to be identified down to species level. Plants simply labelled as Nepenthes accounted for 94 percent of all exported Nepenthes plants between 1988 and 1993. This needs to be remedied and urgent attention is required to close other trade loopholes (2). Nepenthes species, including Nepenthes ephippiata, are being increasingly cultivated, helping to reduce the impact on wild populations. Artificial propagation can help make conservation efforts more effective together with the establishment of more habitat reserves and the implementation and enforcement of protective laws (8).

For more information on Nepenthes ephippiata see:

• Clarke, C. (1997) Nepenthes of Borneo. Natural History Publications, Kota Kinabalu, Malaysia.

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk