You don't have to go far to see the brightest, most beautiful flower. Our lawn is covered in buttercups at the moment. There are so many that it makes them really easy to study. Why not count how many there are in a particular area? Do they all have the same number of petals? Why might their petals be so bright? Can you find some taller ones? Do their leaves look the same? Can you draw one? Are there insects feeding on them? Watch the insects but remember that buttercups are poisonous to humans!
