My Science School

When a dandelion flowers it has a bright yellow head. Gardeners proud of their lawns know this to their cost. To them, dandelions are weeds. The flower stays like this until the whole head has matured. Then it closes up again, to return to the shape it had as a bud. Sometimes it is called a swine’s snout, because it looks like the snout of a pig.

But inside, big changes are taking place. The dandelion’s seeds are growing. When they are all ready, the swine’s snout turns into a snowy-white puff-ball of seeds topped by tuffs of hair. This replaces the yellow flower on top of the stalk. There the seeds wait for the breeze to blow them free, so that they can float off to a new piece of ground and begin growing another dandelion. That is why gardeners are not very fond of them.

 

Picture Credit : Google

Olive branches have been important symbols for thousands of years. Brides getting married in ancient Greece used to wear or carry olive garlands, just as present-day ones carry orange blossom. Winners at the ancient Olympic Games used to be rewarded with a crown of olive too. The story goes that the goddess after whom Athens was named presented the city with an olive branch. It has been a mark of peace and plenty ever since.

Other parts of the ancient world thought olive branches were important too. In the story of the Flood, the first sign of life as the waters went down was an olive leaf. Noah let a dove out of the ark to see what it could find, and back it came with an olive leaf – a sign that God was restoring life to the drowned world.

 

Picture Credit : Google

Lemmings are small rodents found in America, northern Europe and Asia. A lot of them live in Norway. Over the years, they developed a nutty reputation from throwing themselves off cliffs or into rivers. This mass destruction looks like suicide on a huge scale – but don’t always go for the obvious.

Lemmings do not commit suicide any more than other creatures. What happens is that in years when they have lots to eat, they breed rapidly. Soon there is not enough food to feed them all and they have to move to somewhere else that has more food. Thousands set off in a great wave. On they go, pushed by a desperate need to find fresh supplies of food. This urge becomes so frantic that many do fall into rivers. Some even fall over cliffs into the sea. You can see why people think they might be trying to kill themselves. But the reverse is true. The ones that die are killed trying to find food to stay alive.

 

Picture Credit : Google

Hydrangeas are shrubs with large showy flower heads. The flowers can be various colours, ranging from red to blue. The colour depends on the type of soil they are growing in. If your soil is rich in chemicals known as alkalines, the hydrangea flower will be pink, red or white, depending on the type you are growing. The opposite to alkaline soils are acid soils. Hydrangeas grown in these will produce blue or mauve flowers.

However, gardeners hydrangeas can cheat a bit if they want to. Pink-flowering hydrangeas can be encouraged to turn blue by feeding them a chemical called aluminium sulphate in autumn.

 

Picture Credit : Google