Hypogynous Flower:
The thalamus is convex or conical, the develops at its top. While stamens, petals, and sepals are borne successively below. Such a flower is called Hypogynous.
Perigynous Flower:
The thalamus is a cup-shaped structure, and the ovary is located in the center of the concave thalamus. The other floral parts are inserted on the rim or margin of the thalamus. Such a flower is called Perigynous.
Epigynous Flower:
The cup-shaped thalamus grows upwards and fuses with the wall of the ovary and bears sepals, petals, and stamens on the top of the ovary. Such a flower is called Epigynous.
Hypogynous vs Perigynous vs Epigynous Flower:
| Hypogynous Flower | Perigynous Flower | Epigynous Flower |
| 1. Thalamus is convex or conical | 1. Thalamus is plane or slightly concave | 1. Thalamus is deeply cup-shaped |
| 2. Ovary is situated at the apex of thalamus, other whorls are placed below. | 2. Ovary is situated at the center, other whorls are placed at its level or slightly below. | 2. Ovary is situated at the center of deeply lobed thalamus, other whorls are placed above the level of ovary. |
| 3. Thalamus is free from the ovary wall | 3. Thalamus is free from the ovary wall | 3. Thalamus is fused with the ovary wall |
| 4. Ovary is superior, other members are inferior. | 4. Ovary is superior or half-inferior, other members are inferior. | 4. Ovary is inferior, other members are superior. |