Position of floral parts on thalamus

In a perigynous flower the gynoecium is situated in the centre and the other floral parts are located on the rim of the thalamus almost at the same level; the ovary is then said to be half inferior.
Examples of perigynous flowers are plum, rose and peach.
In guava and cucumber the flowers are epigynous and the ovary is inferior.
In cotton (like china rose and mustard) the flower is hypogynous and the ovary is superior.
Hence the ovary is half inferior in peach.

When the gynoecium is situated in the centre and the other floral parts are located on the rim of the thalamus at almost the same level, the flower is perigynous and the ovary is half-inferior.
Examples of perigynous flowers: plum, rose and peach.
Cucumber and guava have epigynous flowers with an inferior ovary.
Brinjal has a hypogynous flower with a superior ovary.
Hence the ovary is half-inferior in plum.