Technical terms used to describe a flower:
Incomplete: A flower is described as incomplete, if one or more whorls are absent. E.g. Euphorbia
Actinomorphic: If the flower can be divided into two equal halves from any plane of symmetry it is called an actinomorphic flower. E.g. members of Brassicaceae, Solanaceae and Liliaceae family.
Zygomorphic: If the flower can be divided into two equal parts by just one plane of symmetry it is called a zygomorphic flower. E.g. members of the Fabaceae family.
Asymmetric: When the flower cannot be divided into two equal halves by any plane of symmetry.