NepenthesThe genus Nepenthes (Tropical Pitcher Plants) contains roughly 80-100 species, (depending on author), several natural and many cultivated hybrids. They are plants of the old world tropics, ranging from S. China, Indonesia, Malaysia, westward to Madagascar (2 species), Seychelles (1), south to Australia (1), New Caledonia (1), north to India (1) and Sri Lanka (1). The greatest diversity occurs on Borneo and Sumatra with many endemic species. Many are plants of hot humid lowland areas, but the majority are tropical montane plants, receiving warm days but cool to cold humid nights yearround. A few are considered tropical alpine with cool days and nights near freezing.
The plants usually consist of a shallow root system, a prostrate or climbing stem, often several meters long, usually 1 cm or less in diameter, larger in a few species (ex. N. bicalcarata). From the stems are leaf-like expanded petioles, similar to certain Citrus sp., ending in a tendril, which in some species aids in climbing, and at the end of which forms the pitcher, considered the true leaf. The pitcher starts as a small bud and gradually expand to form a globe or tube shaped trap. The trap contains fluid of the plants own production, which may be watery or like syrup and is used to drown the prey. The lower part of the trap contains glands which absorb nutrients from captured prey. Above this is a waxy zone, to prevent escape. Surrounding the entrance to the trap is a structure called a peristome, (the "mouth") which is slippery and often quite colorful, attracting prey but offering a poor footing. Above the peristome is a lid, in many species this keeps rain from diluting the fluid within the pitcher, and the underside of lids (and other parts of the plants) contain nectar glands which attract prey. Plants may contain several different types of pitchers, lower traps which typically sit on the ground usually are larger and more round, hanging pitcher are more funnel-shaped, usually smaller and may be colored differently. Frequently there are intermediates between the two types. In some species (N. rafflesiana) different prey may be attracted by different types of pitchers. Prey consists of insects, only the largests species (N. rajah, merrilliana, etc.) may occasionally catch rats or other vertebrates, and possibly accidently. Flowers occur in racemes or more rarely panicles with male and female flowers on separate plants. Seed is produced in a three-sided capsule which may contain 10-60 or more seed, consisting of a central ovary and two wings, one on either side. Seeds are wind distributed.
Nepenthes may be cultivated in greenhouses. Easier species are N. alata, N. ventricosa, N. rafflesiana and N. tobaica. They respond best to pure water, bright light (not full sun), a well drained but moisture holding media*, good air circulation and a relatively high humidity. Highland species must have nighttime cooling to thrive long-term. Chemical fertilizers are probably best avoided or used at low strength. Insect feeding with frozen (thawed before use) crickets seems best if not overdone.
- Media can consist of the following: fir bark, horticultural charcoal, cypress bark, perlite and/or sphagnum moss in various mixes depending on climate.