Pitcher plant  (Nepenthes macfarlanei)

Classified as Vulnerable (VU) on the IUCN Red List 2006 (1) and listed on Appendix II of CITES (3).

Nepenthes macfarlanei is a large, colourful member of the Nepenthes genus (4), a group of spectacular carnivorous pitcher plants equipped with large, modified, pitcher-shaped leaves that trap and digest small organisms (5). These deadly traps hang from coiled tendrils, and are filled with acidic digestive juices. In order to prevent the digestive liquid from being diluted by rainwater, the pitchers are covered by small lids as they grow, which open up when the pitchers are fully developed (5). N. macfarlanei usually produces beautiful green lower pitchers decoratively splashed with reddish-brown speckles (6). The lower surface of the lid is densely covered with short, white hairs, and the lip (peristome) of the pitcher mouth is distinctively toothed (2) (6).

A highland species found in the eastern mountain ranges of Peninsula Malaysia (7) (8).

Grows on mountain ridges, usually in shady sites on mossy banks at 1,000 to 2,150 m above sea level (1).

Nepenthes pitcher plants have evolved carnivorous habits as the answer to growing in extremely nutrient-poor habitats (5) (9). The plants are able to break down and absorb nitrogen and other nutrients from animals, usually invertebrates such as insects, that fall into the pitchers. This supplements any nutrition gained from the soils and therefore allows these plants to survive where others may not. Nepenthes plants attract their prey with nectar, aromas and visual signals such as colour (5). The brim of the pitcher, the peristome, produces the highest amount of nectar, and animals stepping on the slippery, waxy surface of the peristome often fall in. There, unable to escape, they drown in the pitcher fluid and their bodies are broken down by digestive enzymes (9).

Nepenthes are dioecious, meaning that there are separate male and female plants. Likely pollinators include flies, moths, beetles, bugs and ants, which have all been observed visiting the flowers. The fruit takes around three months to develop, and can contain 500 or more seeds, which are very light and have long wings, and are carried by the wind to aid dispersal (9).

The main threat to tropical pitcher plants (Nepenthes) is habitat destruction. However, as popular ornamental plants, they are also widely collected from the wild, and due to their low population numbers, commercial collection and illegal trade has had a serious impact (5).

All Nepenthes species are listed on Appendix II of the Convention on International Trade in Endangered Species (CITES), which restricts the legal trade of these plants. Methods have also been developed to produce tropical pitcher plants from tissue culture, and the horticulture and cultivation of plants produced by this process may significantly help reduce the impact on wild populations (5). Furthermore, most, if not all, of the N. macfarlanei populations occur within protected areas (1).