Aimee Williams, of Russell St School, asks :-
From where does a flower get its smell?
David Fountain, a botanist at Massey University, responded.
Our own sense of smell allows us to ask this question. We are detecting chemicals - we call the mix of them 'scent'- in the air. So, what is scent, and where does it come from?
Scents from flowers are due to tiny vaporised chemicals flowing into the air from deep inside. Imagine being so tiny you could walk into a flower. There at the bottom on the waxed, shiny surfaces you find a little pocket - a tiny cave in the surface of a petal. Amongst all the other busy chemistry going on inside the cells lining the cave, a mixture of different types of scent chemicals is being put together by enzymes and sent out of the cells. Then, like a misty gas, the chemicals boil away into the air - rather like the lazy steam flowing from your kettle after it has boiled. We give the cave a special name - a nectary. Its really a gland - made from tissue that produces different chemicals than any other tissues in the plant.
Some nectaries produce a mix of gas chemicals, some liquid sugary chemicals. Many flowers produce both so they both smell and provide a sugary reward for animal visitors which bring them pollen. Now, you're full-sized again. Find a yellow buttercup flower, smell the perfume and then gently remove a petal and look for a nectary.