Having adapted to thrive in soils lacking in essential minerals such as nitrogen, potassium and phosphorous, carnivorous plants instead obtain these nutrients by catching and digesting insects and other prey. Species such as drosera uniflora, a carnivorous plant native to Patagonia and the Falkland Islands, use a variety of special adaptations to overcome the mineral deficiencies of their habitats.
How do carnivorous plants capture their prey?
Different genera of carnivorous plants use distinct techniques to capture prey. Some use colorful leaves and sugar secretions to attract insects, while others employ sticky hairs or thorns to seize insects.
Once prey has been caught, these plants generally use digestive enzymes that are released by glands on their leaves to help break down the creature, thus allowing them to absorb necessary nutrients.
Where are carnivorous plants normally found?
450 species of carnivorous plants are found across the globe, with a large proportion located in North America, Asia and Australia. They prefer very wet habitats where their roots remain damp and places that are both sunny and open where there is little competition from other plants.
- This sundew grows a single white flower.
- It uses glands on its leaves to capture insects, releasing a sticky mucilage that both attracts prey and then prevents it from escaping.
- The drosera uniflora has tentacles on its leaves, which suffocate insects and also release the necessary digestive enzymes to help break down and draw nutrients from the captured prey.
- This carnivorous plant lives in areas characterized by bogs and moorlands, preferring a situation with plenty of sun such as the mountainsides of Chile.
Venus flytrap (dionaea muscipula)
- Native to subtropical wetlands with acidic soil, such as those found along the East Coast of the United States, the Venus flytrap is perhaps the most well-known species of carnivorous plant.
- They are very easy to cultivate at home, although Venus flytraps grown indoors must be fed a diet of houseflies or slugs to keep them alive.
- To capture prey, the plant’s leaves have small hairs called sensitive or trigger hairs that react when insects or arachnids climb across them, causing the leaves to snap closed if the prey moves after the initial trigger.
- When closed, the leaves form an airtight seal to prevent the digestive juices from leaking out.
- The Venus flytrap will only begin the process of digestion if the insect or arachnid that it has caught triggers a reaction in a number of hairs on the leaf; this is to stop the plant from wasting energy over inedible matter or prey that is too small to merit the effort of digestion.
Purple pitcher plant (sarracenia purpurea)
- Living along the Gulf Coast of the United States, the purple pitcher plant captures prey in a very different way to the drosera uniflora and the Venus flytrap.
- Their pitchers are up to 12-in. (30cm) in length with a large lip.
- The inside of these pitchers contains a fluid of digestive enzymes.
- These enzymes allow the pitchers to digest any prey that falls inside and are aided in their task by larvae of the Wyeomyia smithii mosquito that also live in the pitchers.
- The purple pitcher plant normally preys on flies, ants, arachnids and moths and these will be digested over the lifespan of the pitcher, which is normally a few months.