What Type of Flower Is a Rose?

Complete Flowers

• Botanists base flower classifications on the presence of four basic flower parts. Complete flowers show all four parts, and incomplete flowers lack at least one of the basic four. A complete flower must have sepals, petals, pistils and stamen. Pistils and stamens respectively refer to the female and male organs of the flower. Modified leaves called sepals enclose the developing bloom in a bud. Petals form the colorful display that attracts pollinating insects. Rose blossoms qualify as complete blooms because rose flowers contain all these four parts.

Perfect Flowers

• Not all flowers contain both functional stamen and pistils, which are the two flower parts necessary for the classification of perfect. Staminate flowers only develop the male organ or stamen and contain no pistils. Pistillate flowers contain the female organ or pistil, but never develop stamen. Some plants called dioecious plants develop only flowers of one sex on any single plant, while monoecious plants show male and female flowers on the same individual. Rose plants bloom with functional male and female parts and thus qualify as perfect. The number of petals in the bloom correlates to the number of stamen, according to botanist Jim Conrad.

Dicots

• The number of petals in the blossom determines whether a flower falls in the dicot or monocot categories. Monocot blooms contain petals in multiples of three, while dicots show petal configurations of four or five parts. Plants in the Rosaceae family develop blooms with five petals or multiples of five petals. The Rosaceae family includes several important sub-families. Apple and pear trees belong to the sub-family pomoidaea, while cherries and nectarines belong to prunoidaea. Roses, blackberries and raspberries belong to the sub-family rosoidaea. All plants in the Rosaceae family qualify as dicots.

Actinomorphic

• Botanists also distinguish between types of flowers by the type of symmetry in the bloom. Flowers could take a form that only divides into two symmetrical parts along one unique axis. These zygomorphic flowers show bilateral symmetry. Plants with radial symmetry divide into equal parts along more than one horizontal axis. Drawing a line from the tip of any of a rose's five bottom petals directly across the flower's center divides the bloom into two equal parts. A rose's radial symmetry identifies the blossom as actinomorphic.