[ ĭ-rĕg′yə-lər ] A flower in which one or more members of a whorl, or of several floral whorls, differ in form from other members. Irregular flowers, such as those of the violet or the pea, are often bilaterally symmetric.

In a regular flower, all of the members of a single whorl, such as the petals, are similar in shape and size. Lilies and the apple tree, for example, bear regular flowers. Compare irregular flower.

The flower with their four principal parts is known as a complete flower. These parts are sepal, petal, pistil, and stamen. The flower that does not possess all the four principal parts is known as an incomplete flower. Some flowers do not have any symmetry and are placed under regular or irregular symmetry.

Examples of irregular flowers include: plants in the pea family, orchids, most violets.

List of Different Types of Flowering Plants

• Annuals. Annuals are plants that grow for only one season. The seeds germinate, grow into seedlings, mature and flower.
• Perennials. Perennials live for several years or longer.
• Trees. Trees that are cultivated for fruit production must flower first to form fruit.

Complete flowers contain four flower parts: petals, sepals, stamen, and pistil. Incomplete flowers are missing one or more of these four parts. It is possible for a perfect flower to be incomplete, but it is not possible for an imperfect flower to be complete.

The flowers of papaya are unsexual (contain either male or female reproductive part) while the Hibiscus flowers are bisexual (contain both male and female reproductive parts).

Hibiscus has unisexual flowers.

Hibiscus flowers are perfect flowers (also known as complete flowers). This means each flower has both male and female reproductive structure, petals, sepals and a receptacle. An imperfect, or incomplete, flower is missing one or more of these features.