Q.Differentiate between a hypogynous and an epigynous flower, giving one example of each.

The distinction is based on the ovary's position relative to the calyx, corolla and androecium on the thalamus.

The position of the ovary relative to the other floral whorls on the thalamus gives rise to different flower types.

In a hypogynous flower, the gynoecium (ovary) occupies the highest position on the thalamus, while the calyx, corolla and androecium are attached below it, at a lower level. The ovary is therefore described as superior, since it sits above the other whorls. Mustard and China rose are examples of hypogynous flowers.

In an epigynous flower the arrangement is effectively reversed: the thalamus grows up and around the ovary, fusing with it, so the ovary appears embedded and the other whorls -- calyx, corolla and androecium -- arise from above the ovary. Here the ovary is described as inferior. Flowers of guava and sunflower ray florets are common examples of epigynous flowers.

(A third type, perigynous, is intermediate: the ovary is half-inferior and the other whorls arise from around it at the same level, as in plum or rose.)

Compare where the ovary sits relative to the point of attachment of calyx/corolla/androecium on the thalamus, and match each case with a standard textbook example.

Mixing up 'superior' and 'inferior' -- superior ovary means it is positioned ABOVE (hypogynous), not that it is physically superior/better; also confusing epigynous with perigynous.