Perfect flowers contain both male and female parts. These flowers do not need another flower to pollinate the plant. Pollen produced by the anther sticks to the stigma, from the action of the wind or when bees and butterflies visit the flower.
Example: Rose, hibiscus, lily, petunia
Imperfect flowers contain only male or only female parts. These flowers cannot produce seeds without the help of another flower.
Example:
Cucumber and summer squash produce both male and female blooms on the same plant; these are called 'monoecious'.
Pistachio and kiwifruit contain male and female reproductive parts on separate plants; these are called 'dioecious'.
