Let's look at a Mustard plant (Brassica campestris) step-by-step: 1. Start with the flower: It has 4 green sepals (the protective outer layer) and 4 yellow petals shaped like a cross. 2. Look inside: You will see 6 stamens. Count them—there are 2 short ones near the edge and 4 tall ones grouped in the center. This is our 'Tetradynamous' feature. 3. Look at the ovary: It is placed at the top of the flower, which we call 'Superior Ovary'. 4. Fertilization happens: The ovary swells and turns into a long, thin, green pod (Siliqua). 5. Maturing: As the pod dries, it splits into two halves, dropping the small round black seeds into the soil to grow more mustard plants.