Why is salvia sepals also described as petaloid?

A stamen is one of the basic parts of the flower. Stamens are usually referred to as the male reproductive part of the flower. Each stamen has mainly two parts anther and filament. Sometimes the filaments of stamens are attached with the petals to some extent. Such stamens are called epipetalous stamens. Example: Petunia. If the filaments of all the stamens are fused to form a single tube called staminal tube, then the condition is called monadelphous condition Example: China rose.

Sepals of flowers are generally green in color. But in the case of salvia, the calyx gets colored and appears like a petal to attract the insects. The sepal which is the part of the calyx of Salvia flower is described as petaloids because they have a colored sepal which resembles petals, which are a modified leaves.