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Tropical pitcher plants of the genus Nepenthes are among the most ornate and bizarre plants in the world - their carnivorous nature and peculiar shape have attracted the attention of botanists and horticulturalists since the Victorian Age. The genus Nepenthes is widespread in the Malesian Region, with outlying species occurring west to Madagascar and north to India click here to view map . To date nearly 90 species are recognized, displaying a great diversity of forms.
Nepenthes are found in a diversity of habitats, from coastal scrub, limestone cliffs, rainforest and moss-laden cloud forests. Because of their ability to digest insects, Nepenthes thrive in nutrient-poor soils where they face little competition from other plants.
Species from warm low-elevation forests are generally termed "lowlanders" whereas those occurring in cool mountain forests above 1000 meters are often termed "highlanders". In some localities as many as 8 species have been recorded growing together.
Nepenthes are herbaceous plants - most grow as vines climbing other vegetation by means of the curling tendril at the tip of the leaf. The pitchers, which are actually specially modified leaves, are formed at the tips of the tendrils and are often suspended elegantly. Other pitcher plants such as those found in North and South America (genera Sarracenia, Heliamphora and Darlingtonia) are not related to Nepenthes and produce their pitchers in an entirely different manner.
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Though beautiful in form and colour, it is perhaps the carnivorous nature of Nepenthes which is the most fascinating aspect of these remarkable plants. The characteristic pitchers which make Nepenthes unique are superbly designed to lure, capture, kill, and digest their insect prey by means of a carefully designed trapping mechanism. Bright colors and the promise of nectar are an irresistible attractant for many insects. Those which crawl are guided up frilled wings towards the mouth. The pitcher lid, which is often endowed beneath with nectar glands, provides a convenient landing platform for flying insects. Nectar is also secreted beneath the inner peristome lip. This offering brings potential insect prey closer to the dangerous waxy zone, an area on the inside wall of the pitcher coated with minute loose waxy scales. This surface is particularly slippery for most insects, and those which venture onto it in search of more nectar often loose their foothold and fall into the fluid below.
The fluid within a mature open pitcher is a complex mixture of enzymes, bacteria, and prey carcasses. Most of this liquid has been secreted by the plant itself, via the large glands located in the basal half of the pitcher. It is usually slightly viscous (in some species extremely so) and insects soon sink and drown. Enzymatic and bacterial action dissolve the soft tissues of prey, releasing nutrients that are absorbed by the plant. Rainwater, which would otherwise dilute the contents, is prevented from entering by the lid positioned over the pitcher mouth. Plants in the wild often have pitchers which are heavy with accumulated insects, and at least one of the larger species has been recorded catching rats. Despite the fact that pitcher plants prey on insects, a number of animals such as spiders, flies and frogs live within the pitcher and depend upon it as a source of food and shelter.
In recent years there has been a great revival of interest in Nepenthes in the horticultural trade and it has been found that many species are not as difficult to cultivate as once believed. Some have even been successfully grown as houseplants. We have an extensive range of Nepenthes available for both serious collectors and first-time growers - you can find the complete list of plants we stock in our catalogue. |
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