Difference Between Carpel and Pistil in Flowering Plants

There are about 4 million species of flowering plants and all their flowers, irrespective of how pretty they look, have the same function. Flowers are the reproductive parts of an angiosperm plant. They are designed to be attractive in size, color, form, and scent to facilitate pollination.

The reproductive organs within a flower are called stamen and pistil. Most flowers are bisexual and have both functional pistil and stamens. Some flowers are unisexual and have either stamens or pistils. A plant bearing both male and female flowers is called monoecious, while there are dioecious plant species that bear male flowers and female flowers in separate plants. Staminate flowers only have male reproductive parts and similarly, flowers with only female reproductive parts are also called pistillate. 

When we look at flower parts, we describe them as whorls. The outermost whorl is the calyx consisting of the sepals. It is typically for the protection of buds and support. Within it comes the second whorl called corolla made of petals. Further, inside is the third whorl called androecium, which is a group of stamens. The innermost whorl is the gynoecium consisting of pistils. 

What is a Carpel in a Flower?

The names pistil and carpel are often used interchangeably, but they actually refer to different parts of a flower. A carpel is a part of the pistil that comprises the style, stigma, and ovary. In the pistil, the carpel is the ovule bearing leaf-like part extending out to the style. A pistil can have a single carpel (simple pistil) or several carpels (compound pistil). The carpels can even be fused or free. A gynoecium with a single carpel is called monocarpous. When there are multiple free carpels in a pistil, it is called apocarpous, and when these multiple carpels are fused, it is called syncarpous. 

Within the pistil are the carpel's parts, such as the ovary, stigma, and style. For reproduction, the pollen grain produced on another part of the stamen must come in contact with the stigma. This happens through pollination. It can happen within the same flower (self-pollination) or across different flowers (cross-pollination). Following pollination, the pollen grains are transferred to the ovary where fertilization occurs. Thereby, the male gametes and the ovules are fused to form the zygote. The zygote develops into an embryo, and further-on the ovules become seeds, and the ovary becomes a fruit.

Difference Between Carpel and Pistil

The below table is provided to highlight the comparison of pistil vs. carpel.

Did you Know?

The latest research suggests that the world's biggest and rarest flower, Rafflesia, may not have pistils. There are also no significantly identifiable ovary or carpel-like parts in it. They are identified as unisexual flowers, and the male flowers have several small stamens in the central disc-like structure that looks like spikes. The Rafflesia and similarly large, rare Corpse flower (Titan arum) are also the world's smelliest flowers. They smell like rotten meat. They are also extremely rare and bloom in colonies of same-sex flowers for a very short period. Therefore, these flowers need to pollinate successfully within a short time for the survival of the species. Their extremely unpleasant smell not only wards off predators but also attracts pollinators such as dung beetles and carnivorous flies, which are in search of corpses. This way, they can ensure successful pollination despite the distance between the colonies of male and female flowers. 

The reproductive parts of a flower of a plant are called carpel and pistil, and they differ only slightly. Because a carpel is made up of the stigma, style, and ovary, and a pistil is made up of the union of carpels of a single carpel, we may say that a pistil is a fusion of carpels.

The number of carpels can be easily distinguished by counting the styles. The existence of ovaries in flowers, on the other hand, can be used to determine the number of pistils.

The flower is the reproductive component of a plant and represents the angiosperms family. A whole flower has unique reproductive structures that are colored and structured in a certain way. A flower has four whorls: lower whorls, middle whorls, and top whorls.

The reproductive whorls are the two upper whorls that are involved in reproduction. Also, these whorls are made up of microsporophylls and megasporophylls, with microsporophylls being called stamens and megasporophylls being called carpels (angiosperms).

The two bottom whorls are known as accessory whorls since they do not actively assist in the flower's reproduction. The third whorl is the male whorl, called androecium, and the fourth whorl is the female whorl, called gynoecium. The auxiliary pistil protects the vital organs and, more importantly, attracts pollinating insects.

Angiosperm is an area of science concerned with the study of blooming plants, flowers, and other Angiosperm attributes. We will look at the key differences between the two primary sections of the flower, the carpel, and the pistil, as well as a brief description of each.