NEW YORK: On the north coast of the island of Borneo, in a steaming, fetid place called the Pantu peat-swamp forest grow various species of Nepenthes, carnivorous pitcher plants whose natural habitat extends from southern China, Vietnam and Cambodia to the Philippines, New Guinea, northern Australia, New Caledonia, India, Sri Lanka, Madagascar and Seychelles. The most spectacularly coloured and shaped species are found growing as vines on the islands of Borneo and Sumatra, as well as in peninsular Malaysia.
Nepenthes campanulata is the rarest species of carnivorous pitcher plant on Earth. Until quite recently, the plant had not been seen for half a century. It had been collected only once, and the original habitat had been destroyed. Ch’ien a botanist discovered a new habitat in 1997, and until recently he was the only person to have photographed the species.
Tropical pitcher plants grow on nutrient-poor soil, rock or on trees. “The pitcher starts out as a leaf tip and then develops into a tendril with a bud at its distal end,” Ch’ien explained. ”Then the bud gradually grows in size and slowly inflates with air as it fills with a sterile fluid.”
Fully formed pitchers thrive on the flesh of a variety of creatures. “I once found a perfect mouse skeleton in a pitcher of N. rafflesiana,” Ch’ien said. “But the normal diet of a pitcher plant consists of invertebrate prey, such as ants, cockroaches, termites, crickets, beetles, and occasionally even snails and scorpions.”
Flying and crawling insects are initially attracted to the pitcher by a fragrance produced by nectar glands that are situated on the bottom of the exposed lid or along the ribbed lip. This sweetly scented lip, known as the peristome, forms the mouthlike entrance to the pitcher. It is often arrayed with a dramatic ring of inward-facing clawlike appendages that help prevent insects from crawling out of the trap.
The inner surface of the pitcher is covered with a zone of detachable waxy plates that stop most insects from scaling the walls. The waxy plates clog the insect’s feet and prevent them from gaining a grip. Many Nepenthes plants also lure flying insects with a pattern of ultraviolet light on the peristome. This helps ensure that the insect will select a precarious landing zone just above the fluid-filled reservoir.
Nepenthes veitchii grow thickly on wind-sculptured trees. The species has a very pronounced and slightly recurved peristome, which can range in colour from bright yellow to brown, green or red. The peristome can also appear with red-and-green or red-and-white stripes. N. veitchii stems grow straight up tree trunks, climbing to heights of up to 100 feet. Paired leaves hug the tree, like human arms, interlocking tendrils and pitchers for support. Since 1995, Ch’ien has managed a Nepenthes nursery for Malesiana Tropicals, a company in Sarawak that propagates rare pitcher plants from seeds that he collects from the wild.
When asked how this contributes to conservation, Ch’ien used the story of Nepenthes hamata as an example. “Until 1996 Nepenthes hamata, which is a showy and rare Indonesian species, was almost unknown in cultivation,” he said. “The few plants available sold for around $300 to $400 each, and this naturally attracted the attention of local plant collectors and foreigners, who started taking these plants from the wild.”
The species was first identified in 1957 by “Doc” Kostermans, a botanist from the Herbarium Bogoriense in Bogor, Indonesia. But the original habitat, on a remote stretch of the Karangan River in East Kalimantan, was subsequently destroyed by fire. No one had collected seeds, and no plants were in cultivation. N. campanulata (from the Latin campanulatus, which means ‘bell shaped’) had long been thought extinct until Ch’ien spotted it growing high on a Batu Lagu cliff face —Dawn/NYT News Service (c) New York Times.