Carnivorous plants come from a range of climates from the tropical areas of Asia to the temperate regions of Europe and from Central America up to Alaska, as well as Australia and many Pacific islands. In fact, the only continent in which they don’t grow is Antarctica. These varying ranges of plants are widespread but rare and have differing requirements.
True carnivory in plants has evolved independently at least six times with now at least 750 species across 15 genera.
Carnivorous plants derive food by trapping and consuming other living creatures. They grow in extreme conditions, such as poor-quality soils which don’t provide enough nutrients for them to survive, alone. Nitrogen deficient, acidic bogs being typical. They also require adequate sunlight and water. It is only in these conditions that carnivory is favoured as an advantageous adaption. Most other plants are unable to adapt to these poor conditions so carnivorous plants have a competitive advantage.
In such conditions, carnivorous plants have evolved to produce food collection traps, usually intended for insects, that utilize active, semi-active or passive techniques. These techniques include trigger-action traps, sticky pads, pitfalls and suction methods. They are also able to supplement their energy requirements from sunlight through photosynthesis.
Carnivorous plants generally don’t perform well in nutrient-rich soils as they lose out to competitors. Their reliance on structures that have no selective advantage then becomes a handicap. In these conditions, catching insects is inefficient and unreliable compared to more traditional methods employed by other plants. In fact, over time, carnivorous plants may to some degree, try to adapt to these unfamiliar conditions, abandon their carnivorous nature and stop producing traps in favour of obtaining nutrients from the soil.