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Carnivorous Plants: Capturing Prey to Survive
A carnivorous plant is a plant that captures and kills animal life forms to survive. The carnivorous plant actually digests and absorbs the nutrients from the prey that it kills.
What Makes Carnivorous Plants Different?
While carnivorous and non-carnivorous plants rely on sunlight, carbon dioxide, and water to survive, they also differ in remarkable ways.
Carnivorous plants are actually very similar to other types of plants, except for their unique ability to attract and eat prey. For a plant to be classified as a carnivorous, it must fulfill the following two criteria:
- actively attract, capture, and digest prey
- absorb nutrients from prey and, thereby, grow, survive, or produce more or better pollen or seeds.
Over time, plants in bogs and on cliffs (both nutrient-poor environments) adapted carnivorous behavior to survive. Over 600 species of carnivorous plants use one or more of the following methods to attract and trap prey:
- bright colors on traps
- sweet scents
- sticky, gummy, slippery and/or wet parts to trap captured prey
- downward pointing hairs to prevent escape.
Non-carnivorous plants also attract and even capture insects using their flowers as bait. While these plants have toxic compounds that can kill insects, they lack the ability to absorb nutrients from them in the way that carnivorous plants can.
Types of Carnivorous Plants
Carnivorous plants are broken down into two main types of plants: active and passive.
- Active Traps: Active trapping plants use a rapid movement to catch their prey. Some active trap plants, like Venus flytraps, use two lobes that quickly close together to capture prey. Other plants, like bladderworts, use a suction device to pull insects inside.
- Passive Traps: A passive trapping plant doesn’t actually move, but is still able to catch and digest prey. Pitcher plants, also called pitfalls, have tube-like stomachs. Once a pitcher plant lures an insect, the sticky inner lining of the plant traps the insect. Another type of passive trap is a flypaper trap. The flypaper trap uses a sticky substance to catch insects that land on its surface.
Carnivorous Plant Species
Although some carnivorous plant types are rather obscure, several species of carnivorous plants are widely recognized. The following are some of the plants that get the most attention for their unique ability to catch prey.
- Venus fly trap: As one of the most recognizable carnivorous plants, the Venus flytrap has two lobes that are lined with fine bristles. When prey touches these fine bristles, the plant releases water from its inner membrane cells to the outer membrane cells, causing the trap to clamp shut in one swift motion. Insects are caught inside the trap where they eventually die and the plant soaks in their nutrients.
- pitcher plants: These tubular plants are hollow like a straw and attract prey by luring insects to crawl inside of them. Once insects crawl inside, the sticky excretions that line the inside of the plant trap the insects. Like the Venus fly trap, the insects are eventually absorbed into the plant, providing nutrients that it needs to grow.
- sundews: Sundews have flower heads that are similar to other plants. However, unlike other plants, the flower excretes a sticky substance that attracts and traps the insect. The insect eventually dies and is absorbed into the plant for nutritional purposes.
