Every day I get blown away by certain characteristics of plants. There is no lack of drama or intrigue here. From succulents that look like rocks to flowers that smell like carrion to attract pollinators, the botanical world never seems to disappoint. It would be nice to think that plants do this for the pure pleasure of us humans. But this is, of course, not the case. Their reason is simple: survival. I thought it would be fun to look at some of the various ways plants distribute their seeds. Seed development and dispersal methods take high priority and have had a timeless trial-and-error process resulting in ingenious systems for prolonging the species, something us humans could learn a thing or two from!
We all have memories as kids blowing dandelions into the wind. What we were doing was spreading their seeds. Many primitive and early plants used the wind to spread pollen and seeds, and some still do. As more and more creatures roamed the Earth, plants exploited animals to help pollinate their flowers and distribute seeds. (Plant pollination is another fascinating topic that can be explored in a future blog; for now we will stick with the seeds.) With the help of the increasing numbers of fauna, the floral world really began to blossom.
If you want something to go somewhere, wrap it in a delicious package. That is exactly what fruit does. The fruit attracts animals to take it off to another part of the forest with the seeds inside where they can be tossed aside to germinate. That is the tastiest method of seed dispersal, but many others exist. Take, for example, seeds that have barbs or hooks. They attach to a passing animal and get a free ride for a distance and fall off. Nuts are often collected by squirrels and buried, later to be forgotten about and so become trees. Winged seeds use propeller-like motion to glide away from their parent plant. And even some seed pods explode when touched by raindrops, sending their seeds a good distance away!
The bottom line is that plants need their seeds to be put in a good position to germinate and carry on the species. By these clever techniques, they achieve this. It is an area in the natural world often overlooked but should not be forgotten.
Seth Menser is a senior horticulturist at the San Diego Zoo. Read his previous post, Biomimicry: Nature Deals with Fire.