From Seed to Seed:
Plant Science for K-8 Educators
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From Seed to Seed: |
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Dispersal mechanisms
The simplest way for a plant to disperse its seeds is to drop them. This, however, won't do much to extend the range of the plant. Plants compete for every square inch of soil; if a plant simply drops its seeds, another plant (or even the mother plant) may already be occupying that area. And if the area is disturbed, all of the plant's seedlings will be affected.  Many plants have come to rely on the wind to disperse their seeds, carrying them to distant places. When seeds are spread out over a large area, the chances are better that at least some of them will find suitable homes and survive. Our favorite "weed," the dandelion, is a good example of this; each tiny seed 
is held aloft by a little parachute and, as any student knows, a puff
of air sends the seeds up and away. This is one of the many features that
contribute to the tenacious nature of the dandelion.  Maple and ash trees are other examples of plants that depend on wind for seed dispersal. Both produce seeds enclosed in winged fruits that are carried on the wind as they spiral downward. Some orchids, on the other hand, produce such tiny seeds that they are easily carried on the wind with no elaborate structures for buoyancy. |
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