Which of the following flowers is zygomorphic?

• A. Pea
• B. Mustard
• C. Datura
• D. Chilli

Answer: (A)

Floral symmetry is about how many ways a flower can be divided into mirror-image halves. Zygomorphic flowers have a single plane of symmetry, giving a bilaterally arranged appearance, while actinomorphic flowers are radially symmetric with multiple planes of symmetry. The pea flower is zygomorphic because its papilionaceous corolla—banner, two wings, and a keel—forms a shape that is mirror-imaged along one vertical plane. The other flowers show radial symmetry: mustard has a cross-shaped grouping of petals, Datura has a trumpet-like form with several radial planes, and chili flowers have five petals arranged round a central axis. So the pea is the zygomorphic one.