Question: how to tell the difference between monocot and dicot flowers?
Answer: In monocot flowers, the number of petals is 3 or a multiple of 3. In dicot flowers, the number of petals is 4 or 5 or a multiple of 4 or 5. For example, a black-eyed Susan has 21 petals, which is a multiple of 3, so it is a monocot. A wild rose has 5 petals, so it is a dicot.