Thalamus and Fruit Formation
The thalamus, also known as the receptacle, is an important part of the flower that plays a crucial role in fruit formation. It is the enlarged tip of the flower stalk where all the floral parts, such as sepals, petals, stamens, and pistils, are attached. The thalamus provides support and protection to the developing ovary, which eventually matures into a fruit. The specific contribution of the thalamus to fruit formation depends on the type of fruit it produces.

Types of Fruits
There are several types of fruits based on their origin and development. Some of the common types include true fruits, false fruits, aggregate fruits, and parthenocarpic fruits.

True Fruits:
True fruits are formed from the fertilized ovary of a flower. After pollination, the pollen grain germinates on the stigma and produces a pollen tube. This tube carries the male gametes to the ovule, where fertilization takes place. The fertilized ovule develops into a seed, and the ovary surrounding the seed matures into a fruit. In true fruits, the thalamus does not significantly contribute to fruit formation.

False Fruits:
In some plants, the thalamus plays a significant role in fruit formation. These fruits are known as false fruits or pseudocarps. In false fruits, the thalamus, along with other floral parts, contributes to the structure and development of the fruit. The thalamus may enlarge and become fleshy, forming a part of the fruit. Examples of false fruits include apple, pear, and strawberry. These fruits are derived from the thalamus and not the ovary.

Aggregate Fruits:
Aggregate fruits are formed from multiple separate carpels of a single flower. Each carpel develops into a small fruit, and all the fruits are clustered together on the thalamus. Each individual fruit in an aggregate fruit is derived from a separate ovary, while the thalamus remains as a common receptacle. Examples of aggregate fruits include raspberry and blackberry.

Parthenocarpic Fruits:
Parthenocarpic fruits are formed without fertilization. In these fruits, the ovary develops into a fruit without the occurrence of pollination and fertilization. The thalamus may or may not contribute to fruit formation in parthenocarpic fruits, as their development is not dependent on pollination. Examples of parthenocarpic fruits include bananas and seedless grapes.

Therefore, in some plants, where the thalamus contributes to fruit formation, the fruits are termed as false fruits or pseudocarps. These fruits are derived from the thalamus and not the ovary, unlike true fruits.