Symmetry

The symmetry of a flower is generally determined by the shape of its corolla.

If there is only one way you can cut a flower to get mirror-images of the flower, the flower is bilaterally symmetrical.

If there are multiple ways you can cut a flower to get mirror images, the flower is radially symmetrical.

If there are two, and only two ways you can cut the flower to get mirror images, the flower is biradially symmetrical.

Types of symmetry
Flowers with different types of symmetry. Planes of symmetry (ways in which you could cut the flower to get mirror images) are indicated by dashed lines.