How can plants disperse their seeds

A dandelion's seeds can travel more than 5 miles 8 km through the air. The seeds of the dandelion are encased in tiny fruits. If there is no wind, the fruits may spend several days attached to the seed head. What is certainly true is that by blowing on the seeds you are sending them on a faraway journey.

Each fruit has its own feathery parachute to help it float through the air. With wind dispersal, the seeds are simply blown about and land in all kinds of places. To help their chances that at least some of the seeds land in a place suitable for growth, these plants have to produce lots of seeds. Many plants have seeds that use water as a means of dispersal.

The seeds float away from the parent plant. M any aquatic plants and plants that live near water have seeds that can float, and are carried by water. Plants living along streams and rivers have seeds that float downstream, and therefore become germinate at new sites. The size of the seed is not a factor in determining whether or not a seed can float. Some very large seeds, like coconuts, can float. Some small seeds also float. Birds often fly far away from the parent plant and disperse the seeds in their droppings.

Plants like pittosporum have sticky seeds that can be carried away by birds. Humans can also spread seeds if they get stuck to our clothing or shoes — and if we throw fruit pips and stones out of the car window!

How far do the seeds get blown by the fan? Do certain seeds take longer to reach the ground than others? Think about your results. Did some of your designs not work at all fall straight down, without blowing forward? Did some work better than others? What can you do to improve your designs? Can you make changes to your seeds to make them blow even farther? Extra: Have a friend use a stopwatch to time how long it takes the seeds to hit the ground.

This might be easier if you drop the seeds from a higher location. Have a tall adult drop them, carefully stand on a chair or drop them from the top of stairs.

Extra: Use a tape measure to record how far the seeds travel horizontally from where you drop them to where they hit the ground. Which seeds go the farthest? Extra: How do your results change if you change the speed of the fan?

Observations and results You should find that adding light materials to the "seed" can make it fall more slowly and blow farther—however, the shape of the materials is also very important. Build a Cooler. Get smart. Sign up for our email newsletter. Sign Up. With wind dispersal, the seeds are simply blown about and land in all kinds of places. To help their chances that at least some of the seeds land in a place suitable for growth, these plants have to produce lots of seeds.

Many plants have seeds that use water as a means of dispersal. The seeds float away from the parent plant. Mangrove trees live in estuaries. If a mangrove seed falls during low tide, it can begin to root in the soil. If the seeds fall in the water, they are carried away by the tide to grow somewhere else.

They have a hard seed coat that allows them to float down streams and rivers. Birds often fly far away from the parent plant and disperse the seeds in their droppings. Plants like pittosporum have sticky seeds that can be carried away by birds.