Describe the arrangement of floral members in relation to their insertion on thalamus.

The arrangement of floral members in relation to their insertion on the thalamus is known as the floral arrangement or floral structure. This arrangement is typically described in four main parts: the calyx, corolla, androecium, and gynoecium.

1. Calyx: This is the outermost whorl of the flower. It consists of sepals, which are usually green and protect the flower when it is in bud stage. The sepals are attached to the lowermost part of the thalamus.

2. Corolla: This is the second whorl, located just inside the calyx. It consists of petals, which are usually brightly colored to attract pollinators. The petals are attached to the thalamus above the sepals.

3. Androecium: This is the third whorl, consisting of the male reproductive organs, the stamens. Each stamen consists of a filament and an anther, where pollen is produced. The stamens are attached to the thalamus above the petals.

4. Gynoecium: This is the innermost whorl, consisting of the female reproductive organs. It includes one or more carpels, each consisting of an ovary, style, and stigma. The carpels are attached to the topmost part of the thalamus.

This arrangement can vary greatly among different species of plants, and is a key characteristic used in the classification and identification of plants.