Dandelions

Dandelions

Why are dandelions so common? Some people who don't seem to like them in their lawn work at getting rid of them every year. And every year there are more dandelions to get rid of. What is going on here?

Scientists use the word adaptation for the properties of a living thing that help it to survive. For example, people have some adaptations that have made us very successful on earth. We have big brains. We walk on our two legs, leaving our arms and hands free to do other things. Our fingers and thumbs make us able to hold and use tools. These adaptations have helped people make clothes and buildings so that we can live almost anywhere, and to leave written records so that discoveries and inventions can be shared from one generation to another.

What adaptations make the dandelion so successful? First of all, some plants grow well in the shade of a forest and some plants grow well in open sunny spots. In the last few hundred years we have turned a lot of woodland into open, sunny lawns. Plants that are able to grow in the sun have a good chance of being common. Where do you see dandelions--in sunny spots or in shady woods?

Some plants have a circle of leaves right on the ground called a rosette that really stakes out a territory so that other plants can't grow too close. Others have leaves all up and down their stems. Do dandelions claim a territory with a rosette of leaves right on the ground?

Some plants have wide-spreading, shallow roots. Others have one deep root, sometimes called a taproot, that goes straight down. Which type of root system does a dandelion have? Does this make them easy or hard to pull up?

Some plants that grow tall die if they are cut down. Cutting them down takes off all their leaves so they can't make food for themselves. Look at a dandelion. Where are its leaves? Will a lawn mower cutting a dandelion or a hungry cow eating a dandelion plant remove all of its leaves? What about cutting a dandelion's flowers off, is it able to grow more afterwards or is it finished flowering then? How can you find out? Dandelions growing where they don't get mowed have long flower stems. What about dandelions that have been mowed do they have long or short stems? Why would this help dandelions survive?

Plants compete with one another to get their pollen moved around because most flowers will not make seeds without being pollinated. Do you think dandelion flowers are easy for bees and other insects to find? Scientists have found that dandelion flowers can make seeds even if they have not been pollinated. Will this help them be more common than other plants?

Some plants make only a few seeds; others make a lot of seeds. Which does a dandelion plant do? Why would this help make dandelions common? Why would having a good way to spread seeds to new places help a plant to be more common? Does a dandelion have a good way to spread its seeds? How do dandelions spread their seeds?

Visit our Spring Wildflowers page for more ideas about exploring plants.
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