Jamie and Alex Crump, from Wivey Carnivorous Plants, on these fascinating tropical pitcher plants, which are a speciality of their nursery. - 14 June 2020
Imagine, if you will, a warm and humid tropical highland forest, with a few sunny clearings; in these clearings tall vining plants growing up the trees with what look like jars/pitchers, of various colours and sizes, hanging on tendrils a few inches long with bends and kinks to aid tree climbing. These are Nepenthes, or Tropical Pitcher Plants, a fascinating genus of carnivorous plants
One of the earliest records of Nepenthes in the wild is from the 17th century, of a plant found growing in Madagascar.
There are at least 159 species and many more hybrids growing in tropical areas of Southeast Asia, with a few species found in the African islands of Madagascar and the Seychelles and also in Australia. Nepenthes tend to be classified as either Lowland, Highland or Intermediate (which are often produced by crossing each of the first 2 types), depending on the altitude at which they grow. They can be found at a range of altitudes from close to sea level to around 2700m, which is the world of the ultra highlanders. This range in altitudes does of course lead to some very different growing conditions, with Lowland plants enjoying the relentlessly hot and humid jungles which are always around 30 C, whilst the highland plants prefer the warm days and cool nights of the cloud forests, and indeed a night time drop in temperature is needed for these plants to stay healthy.
They are all carnivorous; however some have adapted to survive on a range of things from fallen leaves to tree shrew poo. Indeed Nepenthes lowii is even shaped like a toilet, ao that the shrew stands on top to reach the nectar that is on the inside of the lid and as the shrew feeds it in turn feeds the plant from the other other end!
Nepenthes lowii (the shrew toilet!) Photo courtesy of Borneo Exotics.
There are a huge range of Nepenthes hybrids, and two examples are N. ampullaria x maxima, and N. spathulata x spectabilis. These are both lower pitchers, which in the wild would sit on the forest floor, note the hairy ladders running from the base of the pitcher up to the peristome; this is to aid access for ground going prey, which can be anything from small insects such as ants to jungle rats and other large rodents, to the top of the pitcher from where they slip in and fall to the bottom of the pitcher, where they are digested by up to 2 litres of pitcher fluid.
Nepenthes ampullaria x maxima
As the plants start to vine up through the trees they produce intermediate followed by upper pitchers; these are often less colourful and smaller (but not always), and they generally lack the insect ladder up the side as these pitchers are designed for flying prey. We often get asked at shows and fairs how long it takes for the lid to open again after the pitcher has caught lunch; the answer is it doesn't move at all, as the prey is trapped only by viscous fluid and slippery pitcher walls.
Nepenthes spathulata x spectabilis
When growing in protected conditions in the UK, they need some slightly specialised conditions compared to most other carnivorous plants which are normally temperate bog plants. Nepenthes don't need to stand in water or need peat-based composts, and being tropical plants temperature, humidity and light are very important factors. All Nepenthes need high humidity (somewhere between 60 and 80% is ideal); however, temperature is where Lowland and Highland plants differ, with Lowlanders need temperatures constantly in high 20's - low 30 's C, whilst Highland plants like mid 20's C during the day with a night time drop of around 10c. As they tend to grow in jungle clearings light levels should be bright but not baking sun.
Nepenthes villosa. Photo courtesy of Borneo Exotics.
The substrate they like to grow in is quick draining, usually containing bark, perlite and sphagnum moss (dried or alive); basically the sort of texture and drainage you would find in the axis of a tree branch or at the base of a jungle tree.
Due to the number of hybrids currently available propagation is often best done via cuttings. Seed viability can be fairly low, and they are often slow to germinate, however you do however have a chance of producing a unique and superb looking plant.
In this article I have only given a brief overview of these fantastic plants, I hope you have enjoyed reading, and maybe consider growing some Nepenthes of your own.
Jamie and Alex Crump own Wivey Carnivorous Plants, based near Wiveliscombe in Somerset, and specialise in Nepenthes, Sarracenia and Dionaea. During the current restrictions plants can be purchased by mail order.