Flower is a modified shoot:
Although, a flower isn’t similar in external appearance to a vegetative shoot on the basis of the origin, position, and structure of both. The flower is considered a modified shoot. The flower is a modified shoot which may be confirmed from the following points:
1. Axis Nature of the Thalamus:
i. The axis nature of the thalamus isn’t very clear as the internodes are so condensed. But in certain exceptional cases, the internodes are elongated showing the stem character. Such types of internodes are seen in Cleome gynandra, Capparis sepiaira, Passiflora suberosa, etc.
ii. The growth of the thalamus is limited by the carpels but sometimes the thalamus grows beyond the gynoecium and bears a leafy shoot or a flower above the first flower. Such monstrous development has been seen in rose, pear, and some other cases.
iii. In Michelia Champaca, Polyalthia longifolia, etc, the region of the thalamus bearing carpels elongates like an ordinary stem giving rise to an aggregate fruit.
iv. The internal structure of the shoot and the thalamus is similar and the vascular supply to floral leaves resembles the vascular supply of leaves.
2. Leaf Nature of Floral Leaves:
The sepals, petals, stamens, and carpels exhibit their leaf nature in the following:
i. The floral leaves are borne on the thalamus in the same pattern as the leaves on the stem. They may arise in whorls or spiral fashion.
ii. The four types of floral members (sepals, petals stamens, and carpels) and foliage leaves often change from one to the other.