Elementary Lessons on Carnivorous Plants

What are Carnivorous Plants?

• Carnivorous plants eat meat but also require water for food. They are sometimes also called insectivorous plants since their main food source are insects, but they also can eat any small animals that can fit in their "mouths" including mice, crustaceans, lizards and spiders. There are over 630 species of plants in this category with six basic types of traps. Some traps are active: they move quickly to catch food. Others have passive traps that sit in wait for food to tumble in.

Active Traps

• Snap traps move rapidly when a food source hits their mouth, closing up and snapping shut to eat their meal. Bladder traps, also called suction traps, pump water from a sealed trap and make a vacuum. The vacuum activates when prey is near and it sucks in the prey. While many of these are underwater plants, some are land-based as well. Adhesive-style traps can be active or passive. These often appear flowery but are sticky, like fly paper. As soon as prey lands on them, they are stuck for good. The plant will sometimes sit passively as the bug is digested or may slowly curl and bring the bug into the digestive system.

Passive Traps

• Passive traps have a system of disguises and tricks to entice prey to them. Some look like flowers waiting to be pollinated, but as soon as the insect touches them, they find they've been fooled into becoming dinner. Pitfall traps, like pitcher plants trap bugs in a rolled leaf full of digestive enzymes. Lobster pot traps, or corkscrew traps, are so called because they work very similarly to a lobster trap. Bugs or little animals get caught in a system of hairs that then move them along into the plant's digestive system. Pigeon traps work in a similar fashion, but have hairs that only move one way, allowing entry but not exit.

Examples

• Although many carnivorous plants can be raised indoors in any climate, maintenance is much easier outdoors.The Venus fly tray (Dionaea muscipula), is probably the most famous of the snap traps. It is a water loving native in the southeastern United States and can grow in swampy outdoor areas within U.S. Department of Agriculture hardiness zones 7 through 10. It most commonly eats flies, but can also eat other types of meat when used as a houseplant. Betty's Bay (Utricularia bisquamata) is suited to USDA zone 9 and is a land-based bladder plant, also called a bladderwort. It produces beautiful little blooms of tiny multicolored flowers and spreads easily in an outdoor garden.The pale pitcher plant (Sarracenia alata), also called the yellow trumpet, another native United States plant. It grows naturally in wet conditions in USDA zones 6 to 8 and is an excellent choice for soggy or boggy areas.