CBSE Class 11-science Answered

A floral formula is a system of representing the structure of a flower using specific letters, numbers and symbols. It represents floral symmetry, number of parts, connation and adnation, insertion, and ovary position. Floral formulas are useful tools for remembering characteristics of the various angiosperm families.  Their construction requires careful observation of individual flowers and of variation among the flowers of the same or different individuals.

A floral formula consists of five symbols indicating from left to right:

• Floral Symmetry
• Number of Sepals
• Number of Petals
• Number of Stamens
• Number of Carpels

The following symbols are used in floral formulae:

Some important points to be remembered while writing floral formulae:

• Fusion is indicated by enclosing the figure in brackets.
• Adhesion is indicated by drawing a line above the symbols of the floral parts.
• The position of the mother axis with respect to the flower is represented by drawing a dot on the top of the floral diagram.

Floral formulae of some important families of flowering plants:

Family Fabaceae:

Family Solanaceae

Family Liliaceae