Flowers grow in a variety of shapes, sizes and scents. All flowers, however, have just one function—to help a plant reproduce itself. Whether a flower is "perfect" has nothing to do with its beauty.
Most flowers have both male and female reproductive organs. The stamen is the male reproductive part; the pistil is the female reproductive part. Flowers that contain a functioning male part and a functioning female part are referred to by botanists as "perfect."
Common Perfect Flowers
According to the University of Illinois College of Agricultural, Consumer and Environmental Sciences, common perfect flowers include those of tomatoes, morning glories, snapdragons, petunias, lilies and irises.
Botanists call flowers that contain only one sex organ "imperfect." If the stamen is missing, or under-developed, the flower is considered female. Such flowers are also called pistillate flowers because they have a developed, working pistil but lack a functioning stamen. Those flowers containing only a working stamen are called male, or staminate flowers.
Common Imperfect Flowers
Among imperfect flowers, both pistillate and staminate flowers may grow on the same plant, or the staminate flower may be on one plant and the pistillate flower on another. The University of Illinois website lists squash, corn, clematis and begonias as species with pistillate and staminate flowers on the same plant. Species with staminate flowers on one plant and pistillate flowers on another include asparagus, spinach, willow and cottonwood.