Carnivorous plants

Discover the fascinating world of carnivorous plants – that survive on a diet of insects, frogs, birds – and even small mammals!

Why are plants carnivorous?

The Venus fly trap (Dionaea muscipula) has leaves like a man trap. Wolfgang Stuppy )

Most carnivorous plants live in peat bogs and other areas with swampy acidic soils. Such soils are often deficient in the nutrients which plants need in order to grow well. Carnivorous plants obtain nitrogen from insects which they trap and digest. Their leaves have become specialised to form a variety of traps - these include sticky surfaces, pitchers into which insects fall and active traps that snap shut around their prey. Enzymes secreted by the plant digest the trapped insect, forming a nutrient-rich 'soup' which is then absorbed.

Many carnivorous plants are becoming endangered because their swampy habitats are being drained to provide land for forestry, agriculture and housing. They are also threatened by over - collecting, either for horticulture or floristry.

Habitats

From the mountains of Scotland to the rainforests of Indonesia, there are plants that eat animals. Their natural habitats are usually sphagnum (peat moss) bogs and seasonally or permanently wet, peaty or sandy soils, which are both acidic and low in nutrients.

Insects become stuck on sticky surfaces of sundews (Drosera)

Trapping methods

Plants are static; they cannot 'stalk' their prey. Instead carnivorous plants lure it, trap it, digest it and absorb the nutrients as a sort of soup. Prey is usually insects and other small invertebrates, but occasionally frogs, birds and small mammals may be caught by large tropical species.

There are four methods of trapping:

Snap traps - The Venus fly trap (Dionaea muscipula) has leaves like a man trap. Modified, toothed, leaf tips with sensitive trigger-hairs, snap shut on prey which is digested by enzymes secreted from glands on the inside of the traps.
Pitfall traps - Sarracenia, Cephalotus, Darlingtonia and Nepenthes all use this method. Insects are attracted to the colours and sweet secretions inside the pitchers, but lose their footing on the smooth hairs and waxy surface, falling to the bottom of the pitcher where they are digested, either by plant enzymes or by bacteria.
Flypaper traps - Sticky surfaces are used by the sundews (Drosera) and the butterworts (Pinguicula). Insects are attracted to shiny glands covering the leaves but become covered in sticky, dew-like secretions and cannot escape.
Suction traps - A trapping method used by Utricularia involves an underwater bladder with trapdoor entry. Tiny animals are sucked into the bladder in a rush of water as the trapdoor flies open.

Kew’s carnivorous plant collections

Feeding time

The plants on display at Kew are not given meat to eat at 'feeding time' - there are sufficient midges and other small insects in the glasshouses to supply their needs.

Kew maintains an important collection of carnivorous plants which is used for conservation, scientific research, and education. This extensive collection contains several thousand plants, with representatives of over 225 different types from around the world.

The plants are skilfully nurtured in high-tech facilities within our largest nursery complex, the Tropical Nursery, where different climatic conditions are carefully controlled.

Where to see carnivorous plants at Kew

Zone 9 in the Princess of Wales Conservatory is dedicated entirely to the display of carnivorous plants. Just outside this zone, in the warmer environment of the main Wet Tropics Zone, you will find some of the tropical species, including some of the large pitfall traps of some pitcher plants.

Children are always fascinated by carnivorous plants, which provided the inspiration for many of the activities in Climbers and Creepers, Kew's interactive play zone. Our young visitors can also marvel at a display cabinet of live plants giving an insight into the unique characters of carnivorous plants.