Type of reproduction that involves fusion of gametes that are produced by two parents is called sexual reproduction. Flower is the reproductive part of a plant as it contains the male (androecium) and female reproductive system (gynoecium).
Androecium and gynoecium are the two most important parts of sexual reproduction in plants as they produce the male and female gametes respectively. The most important units in androecium and gynoecium are the anther and ovary as they produce gametes necessary for sexual reproduction in plants.