Most cacti do not have leaves because they grow in a hot, dry environment, with little water. They are able to survive by storing water for long periods of time; they do this through their extensive root system, which absorbs water from the soil when it rains. In a typical leaf, there is a large amount of water loss through small openings at the leaf surface (called the stomatas). This water loss, called transpiration, is speeded up with warm temperatures. Cacti have adapted by being leafless, storing water in their stems, developing waxy skin to seal in moisture, and growing spines, a form of leaf modification. Spines help shade the rounded or ribbed stems from the blazing sun of their desert habitat. They also protect desert animal species by providing them with shelter.
- What is the difference between a meteor and a shooting star?
- How do nettles sting?
- How was hemlock used to poison in ancient times?
- Is poison ivy really poisonous?
- How many poisonous plants are there in the world?
- How do plants defend themselves?
- Does a Venus flytrap really snap up live flies?
- Is the Amazing Flynapping Arum of Sardinia a circus performer?
- Which plants drown bugs?
- How do carnivorous plants digest their prey?
- What are carnivorous plants?
- What is an asteroid?
- Are all flowers fragrant?
- Which flowering plant can you float on?
- Which is the smallest flower in the world?
- What it the largest flower in the world?
- Can you eat flowers?
- Do all flowers close up at night?
- What makes a plant bloom at the right time of year?
- Why are so many flowers brightly colored?
